[0001] The present invention relates to an apparatus and a method for separating at least
two discrete volumes of composite liquid into at least two components.
[0002] The apparatus and a method of the invention are particularly appropriate for the
separation of biological fluids comprising an aqueous component and one or more cellular
components. For example, potential uses of the invention include: extracting a plasma
component and a cellular component (including platelets, white blood cells, and red
blood cells) from a volume of whole blood, the cellular component being subsequently
filtered so as to remove platelets and white blood cells from the red blood cells;
extracting a plasma component, in which a substantial amount of platelets is suspended,
and a red blood cell component from a volume of whole blood, the white blood cells
being subsequently removed by filtration from the platelet component and the red blood
cell component; extracting a plasma component, a platelet component, and a red blood
cell component from a volume of whole blood, the white blood cells being subsequently
removed by filtration from the platelet component and the red blood cell component.
[0003] An apparatus for processing blood components is known from document
WO 03/089027. This apparatus comprises a centrifuge adapted to cooperate with an annular separation
bag connected to at least one product bag, e.g. a platelet component bag. The centrifuge
includes:
- a rotor having a turntable for supporting the separation bag, and a central compartment
for containing the product bag connected to the separation bag; and
- a squeezing system for squeezing the separation bag and causing the transfer of a
separated component (e.g. platelets suspended in plasma) from the separation bag into
the product bag.
[0004] With this apparatus, a single discrete volume of blood is processed at once.
[0005] An object of the present invention is to design a separation apparatus that can process
at once at least two discrete volumes of a composite liquid, in particular discrete
volumes that may be not the same, and with the proportions of the various components
of the composite liquid that may vary from one discrete volume to another one.
[0006] According to the invention, a method for separating at least two discrete volumes
of a composite liquid into at least a first component and a second component comprises:
- enclosing in at least two separation cells mounted on a rotor at least two separation
bags containing two discrete volumes of a composite liquid respectively;
- storing in a container included in the rotor at least two first satellite bags connected
to the at least two separation bags respectively;
- rotating the rotor; and
- transferring a volume of hydraulic liquid into at least two interconnected expandable
hydraulic chambers located in the at least two separation cells respectively, whereby
the hydraulic liquid gets distributed under centrifugation forces in the at least
two interconnected hydraulic chambers so as to substantially balance the rotor.
[0007] Other features of the method according to the invention are as follows:
- Transferring a volume of hydraulic liquid into the at least two interconnected hydraulic
chambers comprises transferring a predetermined volume of hydraulic liquid.
- Transferring a volume of hydraulic liquid into the at least two interconnected hydraulic
chambers comprises pumping hydraulic liquid into the at least two interconnected hydraulic
chambers.
- Transferring a volume of hydraulic liquid into the at least two interconnected hydraulic
chambers comprises connecting a source of hydraulic liquid to the at least two interconnected
hydraulic chambers so that a rotation of the rotor causes hydraulic liquid to be transferred
from the source of hydraulic liquid into the at least two interconnected hydraulic
chambers.
- Rotating the rotor comprises rotating the rotor at a sedimentation speed at which
the at least first and a second components sediment in each of the separation bags.
- The method further comprises:
- transferring a first separated component from the at least two separation bags into
the at least two first satellite bags connected thereto respectively; and
- balancing any unbalance of the rotor caused by the transfer of the first separated
component into the at least two first satellite bags.
- Balancing any unbalance of the rotor caused by the transfer of the first separated
component into the at least two first satellite component bags comprises respectively
storing the at least two first satellite bags in the container against at least two
interconnected flexible pouches containing a volume of a liquid secured to a wall
of the container, whereby the at least two first satellite bags press against the
at least two pouches under centrifugation forces and distribute the volume of liquid
in the at least two pouches so as to balance the rotor.
- Transferring a first separated component from the at least two separation bags into
the at least two first satellite bags connected thereto respectively comprises:
- squeezing the at least two separation bags within the at least two separation cells
so as to cause a transfer of at least one fraction of the first component into the
at least two first satellite bags connected thereto;
- detecting a characteristic of a component at a first determined location in each separation
bag;
- stopping transferring the at least one fraction of the first component from each separation
bag into the first satellite bag connected thereto, upon detection of the characteristic
of a component at the first determined location.
- The method further comprises changing a speed of the rotor after detecting a characteristic
of a component at the first determined location in the separation bag in which such
detection occurs last.
- The method further comprises changing a speed of the rotor after a predetermined period
of time after detecting a characteristic of a component at the first determined location
in one of the at least two separation bags.
- The method further comprises:
- transferring a second separated component from the at least two separation bags into
at least two second satellite bags connected thereto respectively; and
- balancing any unbalance of the rotor caused by the transfer of the second separated
component into the at least two second satellite bags.
- Balancing any unbalance of the rotor caused by the transfer of the second separated
component into the at least two second satellite component bags comprises respectively
storing the at least two second satellite bags in the container against the at least
two interconnected flexible pouches containing a volume of a liquid secured to a wall
of the container, whereby the at least two second satellite bags press against the
at least two pouches under centrifugation forces and distribute the volume of liquid
in the at least two pouches so as to balance the rotor.
- Transferring a second separated component from the at least two separation bags into
the at least two second satellite bags connected thereto respectively comprises:
- squeezing one of the at least two separation bags within one of the at least two separation
cells so as to cause a transfer of the second component into the second satellite
bag connected thereto;
- detecting a characteristic of a component at a second determined location in either
the squeezed separation bag or a tube connecting the squeezed separation bag to a
second satellite bag;
- stopping squeezing the squeezed separation bag upon detection of the characteristic
of a component at the second determined location; and
- successively repeating the above steps with each separation bag of the at least two
separation bags.
- The method further comprises stopping rotating the rotor after detecting a characteristic
of a component at the second determined location in the separation bag or the tube
connected thereto in which such detection occurs last.
- The method further comprises stopping rotating the rotor after a predetermined period
of time after detecting a characteristic of a component at the second determined location
in one of the at least two separation bags or the tube connected thereto.
[0008] According to the invention, an apparatus for separating at least two discrete volumes
of a composite liquid into at least a first component and a second component comprises
a centrifuge comprises:
- a rotor having a rotation axis, comprising
- at least two separation cells, each for containing a separation bag containing a volume
of composite liquid; and
- a first balancing means for balancing the rotor when the respective weights of the
at least two separation bags in the at least two separation cells are different, comprising:
- at least two expandable hydraulic chambers within the at least two separation cells
respectively, and the at least two hydraulic chambers are fluidly interconnected;
- a source of hydraulic liquid fluidly connected to the at least two hydraulic chambers;
and
- a liquid transferring means for transferring a volume of hydraulic liquid from the
hydraulic liquid source into the at least two interconnected hydraulic chambers so
as to substantially balance the rotor when two separation bags respectively contained
in the at least two different separation cells have different weights.
[0009] Other features of the apparatus according to the invention are as follows:
- The apparatus according further comprises a control unit programmed for causing the
liquid transferring means to transfer a predetermined volume of hydraulic liquid from
the hydraulic liquid source into the at least two interconnected hydraulic chambers,
and the predetermined volume of hydraulic liquid is selected so as to substantially
balance the rotor whatever the weights of two separation bags respectively contained
in the at least two different separation cells.
- The liquid transferring means comprises a pumping means for pumping a volume of hydraulic
fluid into the at least two interconnected hydraulic chambers.
- The source of hydraulic liquid is fixed with respect to the rotor and is fluidly connected
to the at least two hydraulic chambers through a rotary seal.
- The liquid transferring means comprises a motor for driving the rotor in rotation
and the source of hydraulic liquid is fixed with respect to the rotor, below the at
least two separation cells, and is fluidly connected to the hydraulic chambers through
a rotary seal, whereby a rotation of the rotor causes the volume of hydraulic liquid
to be transferred from the hydraulic liquid source into the hydraulic chambers.
- The first balancing means further comprises a valve fitted on a conduit between the
source of hydraulic liquid and the rotary seal, for controlling a transfer into the
hydraulic chambers of a predetermined volume of hydraulic liquid for balancing the
rotor.
- The at least two hydraulic chambers are interconnected by a circular conduit centered
on the rotation axis, and the circular conduit is connected to each hydraulic chamber
to an area thereof that is closer to a periphery of the rotor than to the rotation
axis.
- The liquid transferring means comprises a motor for driving the rotor in rotation,
and the source of hydraulic liquid comprises a reservoir for hydraulic liquid that
is mounted on the rotor and is so designed and fluidly connected to the at least two
hydraulic chambers that a rotation of the rotor causes a transfer of hydraulic liquid
from the reservoir into the at least two hydraulic chambers.
- The reservoir comprises a housing defining an internal volume that is symmetrical
with respect to the rotation axis and a circular inner area that is the farthest to
the rotation axis, and the at least two hydraulic chambers are in fluid communication
with this circular area of the reservoir.
- The apparatus further comprises:
- a storage means included in the rotor for storing at least two satellite bags respectively
connected to at least two separation bags contained in the at least two separation
cells; and
- a component transferring means for transferring at least one separated component from
each separation bag into a satellite bag connected thereto.
- The component transferring means comprises a pumping means for pumping hydraulic liquid
from the source of hydraulic liquid into the at least two interconnected hydraulic
chambers so as to squeeze the at least two separation bags within the at least two
separation cells and to cause a component separated therein to flow into a satellite
bag connected to each separation bag.
- The source of hydraulic liquid is fixed with respect to the rotor, below the at least
two separation cells, and is fluidly connected to the at least two hydraulic chambers
through a rotary seal, and the component transferring means comprises:
- a motor for driving the rotor in rotation; and
- at least one valve member associated with each separation cell for selectively allowing
or blocking a flow of fluid between a separation bag and a satellite bag,
whereby a rotation of the rotor causes hydraulic liquid to be transferred from the
hydraulic liquid source into the at least two hydraulic chambers and to squeeze the
at least two separation bags within the at least two separation cells, which causes
a component separated in a separation bag to flow into a satellite bag connected thereto
when the valve member for allowing or blocking a flow of fluid between the separation
bag and the satellite bag is open.
- The source of hydraulic liquid comprises a reservoir for hydraulic liquid that is
mounted on the rotor and is fluidly connected to the at least two hydraulic chambers,
and the component transferring means comprises:
- a motor for driving the rotor in rotation; and
- at least one valve member associated with each separation cell for selectively allowing
or blocking a flow of fluid between a separation bag and a satellite bag,
whereby a rotation of the rotor causes hydraulic liquid to be transferred from the
reservoir into the at least two hydraulic chambers and to squeeze the at least two
separation bags within the at least two separation cells, which causes a component
separated in a separation bag to flow into a satellite bag connected thereto when
the valve member for allowing or blocking a flow of fluid between the separation bag
and the satellite bag is open.
- The apparatus further comprises a second balancing means for balancing the rotor when
the at least two satellite bags stored in the storing means cause an unbalance of
the rotor.
- The storage means comprises a central container around which the at least two separation
cells are symmetrically arranged with respect to the rotation axis; and
- The second balancing means comprises at least two interconnected flexible pouches
partially filled with a liquid, and the pouches are arranged against a wall of the
central container so that the at least one satellite bag connected to each separation
bag presses onto a pouch during centrifugation.
- The storage means comprises a central container around which the at least two separation
cells are symmetrically arranged with respect to the rotation axis; and
- The second balancing means comprises a cylindrical flexible pouch partially filled
with a liquid lining a wall of the central container so that the at least one satellite
bag connected to each separation bag presses onto the pouch during centrifugation.
- The storage means comprises one container associated with each separation cell, the
container being located between the separation cell and the rotation axis; and
- The second balancing means comprises one flexible pouch partially filled with a liquid
arranged against a wall of each container so that a satellite bag stored in the container
presses onto a pouch during centrifugation, and a flexible pouch in one container
is fluidly interconnected wit a pouch in another container.
- The apparatus further comprises:
- a storage means included in the rotor for storing at least two first satellite bags
respectively connected to at least two separation bags contained in the at least two
separation cells; and
- at least one valve member associated with each separation cell for selectively allowing
or blocking a flow of fluid between a separation bag and a first satellite bag, and
the at least one valve member is mounted on the rotor so as to be between the associated
separation cell and the storage means, with respect to the rotation axis.
- The apparatus further comprises:
- a storage means included in the rotor for storing at least two first satellite bags
respectively connected to at least two separation bags contained in the at least two
separation cells; and
- at least one valve member associated with each separation cell for selectively allowing
or blocking a flow of fluid between a separation bag and a first satellite bag, and
the at least one valve member is mounted on the rotor so that the storage means is
between the at least one valve member and the associated separation cell, with respect
to the rotation axis.
- The apparatus further comprises at least one sensor associated with each separation
cell for generating information related to a characteristic of a component separated
in a separation bag within the separation cell.
- The at least one sensor is mounted on the rotor so as to detect a characteristic of
a component in a separation bag contained in the associated separation cell.
- The at least one sensor is mounted on the rotor so as to detect a characteristic of
a component in a tube connected to a separation bag contained in the associated separation
cell.
- Each separation cell comprises a substantially closed cavity having a longitudinal
axis intersecting the rotation axis of the rotor and comprises a portion closer to
the rotation axis of the rotor that is defined by four walls converging towards the
longitudinal axis of the cavity.
- The longitudinal axis of the cavity of each separation cell intersects the rotation
axis of the rotor at an acute angle.
- Each separation cell comprises a cavity having a bottom wall, an upper wall and a
lower wall, and the hydraulic chamber is underneath a membrane that is lining at least
part of either the upper wall or the lower wall of the cavity.
- Each separation cell comprises a cavity having a bottom wall, an upper wall, and a
lower wall, and the hydraulic chamber comprising a flexible pouch that rests at least
on part the lower wall.
- The density of the hydraulic liquid is so selected as to be higher than the density
of the component having the highest density.
- Each separation cell comprises a cavity having a bottom wall, an upper wall, and lower
wall, and the hydraulic chamber is defined by an elastic socket that is secured to
the separation cell so as to extend between the upper wall and the lower wall.
- The density of the hydraulic liquid is so selected as to be between the density of
a first component and the density of a second component.
- Each separation cell comprises a securing means for securing an upper edge of a separation
bag so that the upper edge is the portion of the separation bag that is the closest
to the rotation axis.
- The apparatus further comprises:
- at least one sensor associated with each separation cell for generating information
related to a characteristic of a component separated in a separation bag within the
separation cell;
- a memory unit for storing at least one change in rotation speed of the rotor; and
- a control unit programmed:
- for receiving from the memory the at least one change in rotation speed, and information
generated by the at least one sensor associated with each separation cell; and
- for causing the at least one change in rotation speed in view of information generated
by one of the at least one sensor associated with each of the at least two separation
cells.
- The control unit is programmed for causing the at least one change of rotation speed
in view of information generated by the first of the at least one sensor associated
with the at least two separation cells that detects a characteristic of a component
separated in a separation bag within a separation cell.
- The control unit is programmed for causing the at least one change of rotation speed
in view of information generated by the last of the at least one sensor associated
with the at least two separation cells that detects a characteristic of a component
separated in a separation bag within a separation cell.
- The apparatus further comprises at least one valve member associated with each separation
cell for selectively allowing or blocking a flow of fluid between a separation bag
within the separation cell and a satellite bag connected thereto, and the control
unit is further programmed for causing at least once in a separation process the at
least one valve member associated with a separation cell to block a flow of fluid
between a separation bag within the separation cell and a satellite bag connected
thereto following a detection of the characteristic of a separated component by the
at least one sensor associated with the same separation cell.
- The apparatus further comprises at least one valve member associated with each separation
cell for selectively allowing or blocking a flow of fluid between a separation bag
within the separation cell and a satellite bag connected thereto, and the control
unit is further programmed for causing at least once in a separation process the at
least one valve member associated with a separation cell to allow a flow of fluid
between a separation bag within the separation cell and a satellite bag connected
thereto following a detection of the characteristic of a separated component by the
at least one sensor associated with another separation cell.
- The apparatus further comprises at least one valve member associated with each separation
cell for selectively allowing or blocking a flow of fluid between a separation bag
within the separation cell and a satellite bag connected thereto, and the control
unit is further programmed for:
- causing the rotor to rotate at a sedimentation speed for separating a least two components
in at least two separation bags contained in the at least two separation cell respectively;
- causing the least one valve member associated with each separation cell to allow a
flow of fluid between each separation bag and the satellite bag connected thereto;
- causing the component transferring means to transfer at least a portion of a separated
component from each of the at least two separation bags into the satellite bag connected
thereto;
- causing the least one valve member associated with each separation cell to block a
flow of fluid between the separation bag within the separation cell and the satellite
bag connected thereto, when the sensor associated with the separation cell detects
the characteristic of a separated component.
- The control unit is further programmed for:
- causing the component transferring means to stop transferring a separated component
from the at least two separation bags into the satellite bags connected thereto when
one sensor associated with one of the at least two the separation cells detects the
characteristic of a separated component;
- causing the component transferring means to transfer a separated component from the
at least two separation bags into the satellite bags connected thereto, after the
valve member associated with the separation cell associated with the sensor that has
detected the characteristic of a separated component has blocked a flow of fluid between
the separation bag and the satellite bag connected thereto.
- The at least one sensor comprises a first sensor for detecting a characteristic of
a separated component in a separation bag within a separation cell;
- The least one valve member comprises a first valve member for allowing or blocking
a flow of fluid between a separation bag and a first satellite bag connected thereto;
- The control unit is further programmed for controlling an actuation of the first valve
member in view of information from the first sensor.
- The at least one sensor comprises a second sensor for detecting a characteristic of
a separated component in a tube connecting a separation bag to a second satellite
bag;
- The least one valve member comprises a second valve member for allowing or blocking
a flow of fluid between a separation bag and a second satellite bag connected thereto;
- The control unit is further programmed for controlling an actuation of a second valve
member in view of information from the second sensor.
[0010] According to the invention, a set of bags for separating at least two discrete volumes
of a composite liquid into at least a first component and a second component comprises:
- a collection and separation bag having a median axis, a top and a bottom, for cooperating
with a centrifuge so that the median axis of the collection and separation bag substantially
intersects the rotation axis, the bottom is the farthest from the rotation axis and
the top is the closest to the rotation axis, and the top of the separation bag comprises
two edges converging towards a tip located on the median axis;
- a collection tube having a first end connected to the collection and separation bag;
and
- at least two satellite bags connected to the top of the collection and separation
bag, and at least one satellite bag in which a component is to be transferred during
a rotation of the centrifuge, is connected to the tip of the collection and separation
bag.
[0011] Other features of the set of bags according to the invention are as follows:
- The set of bags further comprises:
- a first flexible tube having:
- a first end connected to a first satellite bag;
- a valve section for engaging a first pinch valve of the centrifuge;
- a second flexible tube having:
- a first end connected to a second satellite bag;
- a valve section for engaging a second pinch valve of the centrifuge; and
- a three-way connector having:
an inlet channel for connection to the collection and separation bag;
a first outlet channel connected to a second end of the first tube, and
a second outlet channel connected to a second end of the second tube,
and the three-way connector is so shaped as to allow a section of either one of the
first outlet channel and the first tube and a section of either one of the second
outlet channel and the second tube to be the closest to the rotation axis when the
first valve section is engaged in the first pinch valve and the second valve section
is engaged in the second pinch valve.
- The section of either one of the first outlet channel and the first tube and the section
of either one of the second outlet channel and the second tube that are the closest
to the rotation axis when the first valve section is engaged in the first pinch valve
and the second valve section is engaged in the second pinch valve, coincide at a meeting
point of the first outlet channel and the second outlet channel.
- The first outlet channel and the second outlet channel are substantially aligned and
the inlet channel is perpendicular thereto.
- The section of either one of the first outlet channel and the first tube that is the
closest to the rotation axis when the first valve section is engaged in the first
pinch valve and the second valve section is engaged in the second pinch valve comprises
a section of the first tube between the three way connector and the first valve section,
and
- The section of either one of the second outlet channel and the second tube that is
the closest to the rotation axis when the first valve section is engaged in the first
pinch valve and the second valve section is engaged in the second pinch valve comprises
a section of the second tube between the three way connector and the second valve
section.
- An angle between the first outlet channel and the inlet channel is between 90 degrees
and 180 degrees, and an angle between the second outlet channel and the inlet channel
is between 90 degrees and 180 degrees.
- The inlet channel, the first outlet channel, and the second outlet channel join in
a central location.
- The first outlet channel connects to the inlet channel at a first location and the
second outlet channel connects to the inlet channel at a second location, the first
location being closer to the rotation axis than the second location when the first
valve section is engaged in the first pinch valve and the second valve section is
engaged in the second pinch valve.
- The bag set further comprises a third tube having a first end connected to the tip
of the collection and separation bag and a second end connected to the inlet channel.
[0012] The third tube comprises a detection section for engaging a cell detector of the
centrifuge.
- The bag set further comprises a breakable stopper connected to the third tube.
- The bag set is for the separation of whole blood into a plasma component, a platelet
component and a red blood cell component, and the first satellite bag is for collecting
the plasma component and the second satellite bag is for collecting the platelet component.
- The bag set further comprises:
- a third satellite bag for collecting red blood cells;
- a third tube having:
- a first section having a first end connected to the top of the collection and separation
bag; and
- a second section having a second end connected to the third satellite bag; and
- a leuko-reduction filter having an inlet connected to a second end of the first section
of the third tube and an outlet connected to a first end of the second section of
the third tube.
- The bag set further comprises a needle connected to a second end of the collection
tube.
[0013] Other features and advantages of the invention will appear from the following description
and accompanying drawings, which are to be considered exemplary only.
[0014] In the accompanying drawings:
Figure 1 is a schematic view of a first set of bags designed for cooperating with
a separation apparatus;
Figure 2 is a schematic view of a second set of bags designed for cooperating with
a separation apparatus;
Figures 3a, 3b are schematic views of two variants of a detail of the set of bags
of figure 2;
Figure 4 is a schematic view, partly in cross-section along a diametral plane, of
a first embodiment of a separation apparatus;
Figure 5 is a top view of the rotor of the separation apparatus of figure 4;
Figure 6 is a perspective view of a first embodiment of a passive balancing unit for
a separation apparatus;
Figure 7 is a perspective view of a second embodiment of a passive balancing unit
for a separation apparatus;
Figure 8 is schematic view, in cross-section along a radial plane, of a separation
cell of the separation apparatus of figures 4 and 5;
Figure 9 is schematic view, in cross-section along a radial plane, of an embodiment
of a separation cell adjacent to a storage container;
Figure 10 is a perspective view of a rotor of a second embodiment of a separation
apparatus;
Figure 11 is a cross-section view of the rotor of figure 10, along a diametral plane;
Figure 12 is a top view of the rotor of figure 10;
Figure 13 is a schematic view, in cross-section along a diametral plane, of a third
embodiment of a separation apparatus;
Figure 14 is schematic view, in cross-section along a radial plane, of a separation
cell of the separation apparatus of figure 13;
Figure 15 is a perspective view of the flexible diaphragm of the separation cell of
figure 14;
Figures 16 to 18 are schematic views, in cross-section along a radial plane, of the
separation cell figure 14 containing a separation bag at different stages of a separation
process; and
Figure 19 is a schematic view, in cross-section along a diametral plane, of a fourth
embodiment of a separation apparatus.
[0015] For the sake of clarity, the invention will be described with respect to a specific
use, namely the separation of whole blood into at least two components, in particular
into a plasma component and a red blood cell component, or into a plasma component,
a platelet component and a red blood cell component. The discrete volume mentioned
hereunder will typically be the volume of a blood donation. The volume of a blood
donation may vary from one donor to another one (450ml plus or minus 10%). It is also
recalled that the proportion of the components of blood usually varies from one donor
to another one, in particular the hematocrit, which is the ratio of the volume of
the red blood cells to the volume of the sample of whole blood considered. In other
words the density of blood may slightly vary for one donor to another one. It should
be understood however that this specific use is exemplary only.
[0016] Figure 1 shows an example of a set of bags adapted to the separation of a composite
liquid (e.g. whole blood) into a first component (e.g. a plasma component containing
or not a substantial amount of suspended platelets) and a second component (e.g. a
blood cell component). This bag set comprises a flexible separation bag 1 and two
flexible satellite bags 2, 3 connected thereto.
[0017] When the composite liquid is whole blood, the separation bag 1 has two purposes,
and is successively used as a collection bag and as a separation bag. It is intended
for initially receiving a discrete volume of whole blood from a donor (usually about
450 ml) and to be used later as a separation chamber in a separation apparatus. The
separation bag 1 is flat and generally rectangular. It is made of two rectangular
sheets of plastic material that are welded together so as to define therebetween an
interior space having a main rectangular portion connected to a triangular top downstream
portion. A first tube 4 is connected to the tip of the triangular portion, and a second
and a third tubes 5, 6 are connected to either lateral edges of the triangular portion,
respectively. The proximal ends of the three tubes 4, 5, 6 are embedded between the
two sheets of plastic material so as to be parallel. The separation bag 1 further
comprises a hole 8 in each of its corners that are adjacent to the three tubes 4,
5, 6. The holes 8 are used to secure the separation bag to a separation cell, as will
be described later.
[0018] The separation bag initially contains a volume of anti-coagulant solution (typically
about 63 ml of a solution of citrate phosphate dextrose for a blood donation of about
450 ml), and the first and third tubes 4, 6 are fitted at their proximal end with
a breakable stopper 9, 10 respectively, blocking a liquid flow therethrough.
[0019] The second tube 5 is a collection tube having a needle 12 connected to its distal
end. At the beginning of a blood donation, the needle 12 is inserted in the vein of
a donor and blood flows into the collection (separation) bag 1. After a desired volume
of blood has been collected in the collection (separation) bag 1, the collection tube
5 is sealed and cut.
[0020] The first satellite bag 2 is intended for receiving a plasma component. It is flat
and substantially rectangular. It is connected to the distal end of the first tube
4.
[0021] The second satellite bag 3 is intended for receiving a red blood cell component.
It is flat and substantially rectangular. It is connected to the distal end of the
third tube 6. The third tube 6 comprises two segments respectively connected to the
inlet and the outlet of a leuko-reduction filter 13. The second satellite bag 3 contains
a volume of storage solution for red blood cells, and the third tube 6 is fitted at
its distal end with a breakable stopper 14 blocking a liquid flow therethrough.
[0022] Figure 2 shows an example of a set of bags adapted to the separation of a composite
liquid (e.g. whole blood) into a first component (e.g. a plasma component), an intermediate
component (e.g. a platelet component), and a second component (e.g. a red blood cell
component). This bag set comprises a flexible separation bag 1 and three flexible
satellite bags 2, 3, 15 connected thereto.
[0023] This second set of bags differs from the set of bags of figure 1 in that it comprises
a third satellite bag 15, which is intended to receive a platelet component, and a
T-shaped three-way connector 16 having its leg connected by the first tube 4 to the
separation bag 1, a first arm connected by a fourth tube 17 to the first satellite
bag 2 (plasma component bag), and a second arm connected by a fifth tube 18 to the
third satellite bag 15 (platelet component bag). Like the first and second satellite
bags 2, 3, the third satellite bag 15 is flat and substantially rectangular.
[0024] Figures 3a, 3b show two variants of the T-shaped three-way connector 16 of the bag
set of figure 2.
[0025] The three-way connector 16a shown in figure 3a has the shape of a regular three-point
star having a first outlet channel 21 and a second outlet channel 22 that are connected
to an inlet channel 20 at an angle of about 120 degrees.
[0026] The three-way connector 16b shown in figure 3b, defines a first outlet channel 21
and a second outlet channel 22 that are perpendicularly connected to an inlet channel
20 and are offset along the inlet channel 20 so that the first outlet channel 21 is
further than the second outlet channel 22 from the end of the inlet channel 20 that
is connected to the first tube 4.
[0027] The three-way connectors 16, 16a, 16b are arranged such that when the separation
bag of figure 2 (or any of its variants represented in figure 3a, 3b) is mounted in
a separation apparatus (to be described in detail below), in which a separation cell
for a separation bag 1, a storage container for the satellite bags 2, 3, 15, and a
first and second pinch valve members for allowing or stopping a flow of liquid in
the fourth and fifth tubes 17, 18 are arranged in this order along a radial direction
from a rotation axis of the separation apparatus, with the pinch valve members being
the closest to the rotation axis. In this particular configuration, when the fourth
and fifth tubes 16, 17 are engaged in the first and second pinch valve members as
shown in figures 2, 3a, 3b, then the three-way connector 16, 16b, or a bend in the
fourth and fifth tubes 17, 18 in the case of the connector of figure 3a, are the closest
portion(s) of the whole bag set to the rotation axis. The results of this disposition
are that, when the separation apparatus rotates, any air in the bag set will gather
in the connector in an area that is the closest to the rotation axis (junction point
of the three channels 20, 21, 22 in the connectors shown in figures 2, 3b) or in the
bends in the fourth and fifth tube 17, 18 between the connector and the pinch valve
members 17, 18 when the connector used is the connector of figure 3a. This air buffer
between the separation bag and the satellite bag will prevent any undesirable siphoning
of contents of a satellite bag into the separation bag under centrifugation forces.
[0028] The three-way connector 16b presents a particular interest when the bag set of figure
2 is used to separate a plasma component and a platelet component. When the plasma
component has been transferred into the first satellite bag 2 and the platelet component
has been transferred into the third satellite bag 15, the connector 16b shown in figure
3b allow for flushing the second channel 22, which may contain remaining platelets,
with a small volume of plasma trapped in the fourth tube 17 between the connector
16b and the first pinch valve member.
[0029] Figures 4, 5, 6, 8 show a first embodiment of an apparatus for simultaneously separating
by centrifugation four discrete volumes of a composite liquid. The apparatus comprises:
- a centrifuge adapted to receive four of either set of bags shown in figures 1 and
2, with the four discrete volumes of a composite liquid contained in the four separation
bags;
- a component transferring means for transferring at least one separated component from
each separation bag into a satellite bag connected thereto;
- a first balancing means for initially balancing the rotor when the weights of the
four separation bags are different; and
- a second balancing means for balancing the rotor when the weights of the separated
components transferred into the satellite bags cause an unbalance of the rotor.
[0030] The centrifuge comprises a rotor that is supported by a bearing assembly 30 allowing
the rotor to rotate around a rotation axis 31. The rotor comprises:
- a cylindrical rotor shaft 32 to which a pulley 33 is connected;
- a storage means comprising a central cylindrical container 34 for containing satellite
bags, which is connected to the rotor shaft 32 at the upper end thereof so that the
longitudinal axis of the rotor shaft 32 and the longitudinal axis of the container
34 coincide with the rotation axis 31, and
- a frusto-conical turntable 35 connected to the upper part of the central container
34 so that its central axis coincides with the rotation axis 31. The frusto-conical
turntable 35 flares underneath the opening of the container 34. Four identical separation
cells 40 are mounted on the turntable 35 so as to form a symmetrical arrangement with
respect to the rotation axis 31.
[0031] The centrifuge further comprises a motor 36 coupled to the rotor by a belt 37 engaged
in a groove of the pulley 33 so as to rotate the rotor about the rotation axis 31.
[0032] Each separation cell 40 comprises a container 41 having the general shape of a rectangular
parallelepiped. The separation cells 40 are mounted on the turntable 35 so that their
respective median longitudinal axes 42 intersect the rotation axis 31, so that they
are located substantially at the same distance from the rotation axis 31, and so that
the angles between their median longitudinal axes 42 are substantially the same (i.e.
90 degrees). The exact position of the separation cells 40 on the turntable 35 is
adjusted so that the weight on the turntable is equally distributed when the separation
cells 40 are empty, i.e. so that the rotor is balanced. It results from the arrangement
of the separating cells 40 on the turntable 35 that the separating cells 40 are inclined
with respect to the rotation axis 31 of an acute angle equal to the angle of the frustum
of a cone that geometrically defines the turntable 35.
[0033] Each container 41 comprises a cavity 43 that is so shaped and dimensioned as to loosely
accommodate a separation bag 1 full of liquid, of the type shown in figures 1 and
2. The cavity 43 (which will be referred to later also as the "separation compartment'')
is defined by a bottom wall, that is the farthest to the rotation axis 31, a lower
wall that is the closest to the turntable 35, an upper wall opposite to the lower
wall, and two lateral walls. The cavity 43 comprises a main part, extending from the
bottom wall, which has substantially the shape of a rectangular parallelepiped with
rounded angles, and an upper part, which has substantially the shape of a prism having
convergent triangular bases. In other words, the upper part of the cavity 43 is defined
by two couples of opposite walls converging towards the central median axis 42 of
the cavity 43. One interest of this design is to cause a radial dilatation of the
thin layer of a minor component of a composite fluid (e.g. the platelets in whole
blood) after separation by centrifugation, and makes it more easily detectable in
the upper part of a separation bag. The two couples of opposite walls of the upper
part of the separation cell 40 converge towards three cylindrical parallel channels
44, 45, 46, opening at the top of the container 41, and in which, when a separation
bag 1 is set in the container 41, the three tubes 4, 5, 6 extend.
[0034] The container 41 also comprises a hinged lateral lid 47, which is comprised of an
upper portion of the external wall of the container 41, i.e. the wall that is opposite
to the turntable 35. The lid 47 is so dimensioned as to allow, when open, an easy
loading of a separation bag 1 full of liquid into the separation cell 40. The container
41 comprises a fast locking means (not shown) by which the lid 47 can be locked to
the remaining part of the container 41.
[0035] The container 41 also comprises a securing means for securing a separation bag 1
within the separation cell 40. The bag securing means comprises two pins 48 protruding
on the internal surface of the lid 47, close to the top of separation cell 40, and
two corresponding recesses 49 in the upper part of the container 41. The two pins
48 are so spaced apart and dimensioned as to fit into the two holes 8 in the upper
corner of a separation bag 1.
[0036] The separation apparatus further comprises a component transferring means for transferring
at least one separated component from each separation bag into a satellite bag connected
thereto. The component transferring means comprises a squeezing system for squeezing
the separation bags 1 within the separation compartments 43 and causing the transfer
of separated components into satellite bags 2, 3, 15.
[0037] The squeezing system comprises a flexible diaphragm 50 that is secured to each container
41 so as to define an expandable chamber 51 in the cavity thereof. More specifically,
the diaphragm 50 is dimensioned so as to line the bottom wall of the cavity 43 and
a large portion of the lower wall of the cavity 43, which is the closest to the turntable
35.
[0038] The squeezing system further comprises a peripheral circular manifold 52 that forms
a ring within the turntable 35 extending close to the periphery of the turntable 35.
Each expansion chamber 51 is connected to the manifold 52 by a supply channel 53 that
extends through the wall of the respective container 41, close to the bottom thereof.
[0039] The squeezing system further comprises a hydraulic pumping station 60 for pumping
a hydraulic liquid in and out the expandable chambers 51 within the separation cells
40. The hydraulic liquid is selected so as to have a density slightly higher than
the density of the more dense of the components in the composite liquid to be separated
(e.g. the red blood cells, when the composite liquid is blood). As a result, during
centrifugation, the hydraulic liquid within the expandable chambers 51, whatever the
volume thereof, will generally remain in the most external part of the separation
cells 40. The pumping station 60 is connected to the expandable chambers 51, through
a rotary seal 69, by a duct 56 that extends through the rotor shaft 32, the bottom
and lateral wall of the central container 34, and, from the rim of the central container
34, radially through the turntable 35 where it connects to the manifold 52.
[0040] The pumping station 60 comprises a piston pump having a piston 61 movable in a hydraulic
cylinder 62 fluidly connected via a rotary fluid coupling 63 to the rotor duct 54.
The piston 61 is actuated by a stepper motor 64 that moves a lead screw 65 linked
to the piston rod. The hydraulic cylinder 62 is also connected to a hydraulic liquid
reservoir 66 having an access controlled by a valve 67 for selectively allowing the
introduction or the withdrawal of hydraulic liquid into and from a hydraulic circuit
including the hydraulic cylinder 62, the rotor duct 56 and the expandable hydraulic
chambers 51. A pressure gauge 68 is connected to the hydraulic circuit for measuring
the hydraulic pressure therein.
[0041] The separation apparatus further comprises four pairs of a first and second pinch
valve members 70, 71 that are mounted on the rotor around the opening of the central
container 34. Each pair of pinch valve members 70, 71 faces one separation cell 40,
with which it is associated. The pinch valve members 70, 71 are designed for selectively
blocking or allowing a flow of liquid through a flexible plastic tube, and selectively,
sealing and cutting a plastic tube. Each pinch valve member 70, 71 comprises an elongated
cylindrical body and a head having a groove 72 that is defined by a stationary upper
jaw and a lower jaw movable between an open and a closed position. The groove 72 is
so dimensioned that one of the tubes 4, 17, 18 of the bag sets shown in figures 1
and 2 can be snuggly engaged therein when the lower jaw is in the open position. The
elongated body contains a mechanism for moving the lower jaw and it is connected to
a radio frequency generator that supplies the energy necessary for sealing and cutting
a plastic tube. The pinch valve members 70, 71 are mounted inside the central container
34, adjacent the interior surface thereof, so that their longitudinal axes are parallel
to the rotation axis 31 and their heads protrude above the rim of the container 34.
The position of a pair of pinch valve members 70, 71 with respect to a separation
bag 1 and the tubes 4, 17, 18 connected thereto when the separation bag 1 rests in
the separation cell 40 associated with this pair of pinch valve members 70, 71 is
shown in doted lines in figures 1 and 2. Electric power is supplied to the pinch valve
members 70, 71 through a slip ring array 38 that is mounted around a lower portion
of the rotor shaft 32.
[0042] The separation apparatus further comprises four pairs of sensors 73, 74 for monitoring
the separation of the various components occurring within each separation bag when
the apparatus operates. Each pair of sensors 73, 74 is embedded in the lid 47 of the
container 41 of each separation cell 40 along the median longitudinal axis 42 of the
container 41, a first sensor 73 being located the farthest and a second sensor 74
being located the closest to the rotation axis 31. When a separation bag 1 rests in
the container 41 and the lid 47 is closed, the first sensor 73 (later the bag sensor)
faces the upper triangular part of the separation bag 1 and the second sensor 74 (later
the tube sensor) faces the proximal end of the first tube 4. The bag sensor 73 is
able to detect blood cells in a liquid. The tube sensor 74 is able to detect the presence
of absence of liquid in the tube 4 as well as to detect blood cells in a liquid. Each
sensor 73, 74 may comprise a photocell including an infrared LED and a photo-detector.
Electric power is supplied to the sensors 73, 74 through the slip ring array 38 that
is mounted around the lower portion of the rotor shaft 32.
[0043] The separation apparatus further comprises a first balancing means for initially
balancing the rotor when the weights of the four separation bags 1 contained in the
separation cells 40 are different. The first balancing means substantially comprises
the same structural elements as the elements of the component transferring means described
above, namely: four expandable hydraulic chambers 51 interconnected by a peripheral
circular manifold 52, and a hydraulic liquid pumping station 60 for pumping hydraulic
liquid into the hydraulic chambers 51 through a rotor duct 56, which is connected
to the circular manifold 52. In order to initially balance the rotor, whose four separation
cells 40 contain four discrete volumes of a composite liquid that may not have the
same weight (because the four volumes may be not equal, and/or the density of the
liquid may slightly differ from one volume to the other one), the pumping station
60 is controlled so as to pump into the interconnected hydraulic chambers 51, at the
onset of a separation process, a predetermined volume of hydraulic liquid that is
so selected as to balance the rotor in the most unbalanced situation. For whole blood,
the determination of this balancing volume takes into account the maximum difference
in volume between two blood donations, and the maximum difference in hematocrit (i.e.
in density) between two blood donations. Under centrifugation forces, the hydraulic
liquid will distribute unevenly in the four separation cells 40 depending on the difference
in weight of the separation bags 1, and balance the rotor. In order to get an optimal
initial balancing, the volume of the cavity 43 of the separation cells 40 should be
selected so that the cavities 43, whatever the volume of the separation bags 1 contained
therein, are not full after the determined amount of hydraulic liquid has been pumped
into the interconnected expansion chambers 51.
[0044] The separation apparatus further comprises a second balancing means, for balancing
the rotor when the weights of the components transferred into the satellite bags 2,
3, 15 in the central container 34 are different. For example, when two blood donations
have the same hematocrit and different volumes, the volumes of plasma extracted from
each donation are different, and the same is true when two blood donations have the
same volume and different hematocrit. As shown in figures 4, 5, 6 the second balancing
means comprises four flexible rectangular pouches 81, 82, 83, 84 that are interconnected
by four tube sections 85, 86, 87, 88, each tube section connecting two adjacent pouches
by the bottom thereof. The pouches 81, 82, 83, 84 contain a volume of balancing liquid
having a density close to the density of the composite liquid. The volume of balancing
liquid is so selected as to balance the rotor in the most unbalanced situation. The
four pouches 81, 82, 83, 84 are so dimensioned as to line the inner surface of the
central container 34 and to have an internal volume that is larger than the volume
of balancing liquid so that the balancing liquid can freely expand in any of the pouches
81, 82, 83, 84. In operation, if, for example, four satellite bags 2 respectively
adjacent to the four pouches 81, 82, 83, 84 receive different volumes of a plasma
component, the four satellite bags 2 will press unevenly, under centrifugation forces,
against the four pouches 81, 82, 83, 84, which will result in the balancing liquid
becoming unevenly distributed in the four pouches 81, 82, 83, 84 and compensating
for the difference in weight in the satellite bags 2.
[0045] The separation apparatus further comprises a controller 90 including a control unit
(e.g. a microprocessor) and a memory unit for providing the microprocessor with information
and programmed instructions relative to various separation protocols (e.g. a protocol
for the separation of a plasma component and a blood cell component, or a protocol
for the separation of a plasma component, a platelet component, and a red blood cell
component) and to the operation of the apparatus in accordance with such separation
protocols. In particular, the microprocessor is programmed for receiving information
relative to the centrifugation speed(s) at which the rotor is to be rotated during
the various stages of a separation process (e.g. stage of component separation, stage
of a plasma component expression, stage of suspension of platelets in a plasma fraction,
stage of a platelet component expression, etc), and information relative to the various
transfer flow rates at which separated components are to be transferred from the separation
bag 1 into the satellite bags 2, 3, 15. The information relative to the various transfer
flow rates can be expressed, for example, as hydraulic liquid flow rates in the hydraulic
circuit, or as rotation speeds of the stepper motor 64 of the hydraulic pumping station
60. The microprocessor is further programmed for receiving, directly or through the
memory, information from the pressure gauge 68 and from the four pairs of photocells
73, 74 and for controlling the centrifuge motor 36, the stepper motor 64 of the pumping
station 60, and the four pairs of pinch valve members 70, 71 so as to cause the separation
apparatus to operate along a selected separation protocol.
[0046] Variants of the first embodiment of the separation apparatus described above are
as follows:
- Instead of the centralized hydraulic squeezing system described above, a separation
apparatus can be fitted with as many independent squeezing means as separation cells
40. An independent squeezing means may be comprised, for example, of a plate that
can be moved by any electro-magnetic, electromechanical or hydraulic mechanism so
as to squeeze a separation bag against a wall of the cavity 43 of the container 41
of a separation cell 40.
- Instead of a system of interconnected hydraulic chambers or pouches, the first and/or
second balancing means can comprise a ball balancer including a circular cage in which
heavy balls can move freely. The circular cage is mounted on the rotor so as to be
centered on the rotation axis 31.
- Instead of a central container 34 for containing all the satellite bags 2, 3, 15 connected
to the separation bags 1, a separation apparatus can comprise as many satellite bag
containers as separation cells. Figure 9 shows a container arrangement that can be
used in such a separation apparatus. The container arrangement of figure 9 comprises
a separation bag container 41 that is connected to or is made integral with a satellite
bag container 54. The satellite bag container 54 comprises a cavity 55 having the
shape of a rectangular parallelepiped, which contains a pouch 81 of a balancing assembly
as shown in figure 6. The separation bag container 41 is superimposed on the satellite
bag container 54 so that the openings of both containers are in the same plane, facing
the rotation axis 31 when the container arrangement is mounted on a rotor turntable
35.
- The second sensors 74 can be embedded in the lids 47 of the containers 41 so as to
face an upper part of a separation bag 1 close to the connection thereof to the first
tube 4.
- The diaphragm 50, instead of being secured to the container 41 so as to line a portion
of the lower wall of the cavity 43, can be secured to the container 41 so as to line
a portion of the upper wall of the cavity 43.
- In each separation cell 40, the hydraulic chamber 51, instead of being defined by
a flexible diaphragm 50 lining the bottom wall of the cavity 43 and a large portion
of the lower wall of the cavity 43, can comprise a flexible pouch similar to a pouch
of the second balancing means.
- The second balancing means, instead of comprising four interconnected pouches 81,
82, 83, 84 as shown in figure 6, can comprise a flexible tubular pouch 80 having two
concentric walls as shown in figure 7. The pouch 80 is so dimensioned as to line the
inner surface of the central container 34 and to have an internal volume that is larger
than the volume of balancing liquid so that the balancing liquid can freely expand
in one area of pouch or in another.
- The pumping station 60, instead of a piston pump 61, 62, can comprise any pump (e.g.
a positive displacement pump) whose output can be controlled with sufficient accuracy.
[0047] Figures 10, 11, 12 show the rotor of a second embodiment of a separation apparatus
for four discrete volumes of a composite liquid.
[0048] The rotor of this second embodiment essentially differs from the rotor of the embodiment
of figures 4 and 5 in the spatial arrangement of the pinch valve members 70, 71 and
of the storage means for the satellite bags with respect to the separation cells 40.
In this embodiment, the storage means, instead of comprising a central container,
comprises four satellite containers 341, 342, 343, 344 that are arranged around a
central cylindrical cavity 340, in which the four pairs of pinch valve member 70,
71 are mounted with their longitudinal axes parallel to the rotation axis 31. The
cavity 43 of a satellite container 341, 342, 343, 344 has a regular bean-like cross-section,
and a central longitudinal axis that is parallel to the rotation axis 31 and intersects
the longitudinal axis 42 of the associated separation cell 40.
[0049] When a set of bag as shown in figures 2, 3a, 3b is mounted on the rotor of figures
11 to 12, the separation bag 1 and the satellite bags 2, 3, 15 are located beyond
the associated pinch valves members 70, 71 with respect to the rotation axis 31.
[0050] The tubes 4, 17, 18 and the three-way connector 16, 16a, 16b connecting the bags
are then in the position shown in figures 2, 3a, 3b.
[0051] The operation of the separation apparatus of figures 3 and 4, in accordance to a
first and second an illustrative separation protocols, will be described now.
[0052] According to a
first separation protocol, four discrete volumes of blood are separated into a plasma component, a first cell
component comprising platelets, white blood cells, some red blood cells and a small
volume of plasma (later the "buffy coat" component) and a second cell component mainly
comprising red blood cells. Each volume of blood is contained in a separation bag
1 of a bag set represented in figure 2, in which it has previously been collected
from a donor using the collection tube 5. After the blood collection, the collection
tube 5 has been sealed and cut close to the separation bag. Typically, the volumes
of blood are not the same in the four separation bags 1, and the hematocrit varies
from one separation bag 1 to another one. Consequently, the separation bags 1 have
slightly different weights.
First stage (first protocol): setting the four bag sets in the separation apparatus
[0053] Four separation bags 1 are loaded into the four separation cells 40. The lids 47
are closed and iocked, whereby the separation bags 1 are secured by their upper edge
to the containers 41 (the pins 48 of the securing means pass then through the holes
8 in the upper corner of the separation bags 1 and engage the recesses 49 or the securing
means).
[0054] The tubes 17 connecting the separations bags 1 to the plasma component bags 2, through
the T connectors 16, are inserted in the groove 72 of the first pinch valve members
70. The tubes 18 connecting the separations bags 1 to the buffy coat component bags
15, through the T connector 16, are inserted in the groove 72 of the second pinch
valve members 71. The four plasma component bags 2, the four buffy coat component
bags 15, the four red blood cell component bags 3 and the four leuko-reduction filters
13 are inserted in the central compartment 34 of the rotor. The four plasma component
bags 2 are respectively placed in direct contact with the pouches 81 to 84 of the
second balancing means. The pinch valve members 70, 71 are closed and the breakable
stoppers 9 in the tubes 4 connecting the separation bags 1 to the T connectors 16
are manually broken.
Second stage (first protocol): balancing the rotor in order to compensate for the difference in weights of the separation
bags
[0055] At the onset of the second stage, all the pinch valve members 70, 71 are closed.
The rotor is set in motion by the centrifuge motor 36 and its rotation speed increases
steadily until it rotates at a first centrifugation speed. The pumping station 60
is actuated so as to pump a predetermined overall volume of hydraulic liquid into
the four hydraulic chambers 51, at a constant flow rate. This overall volume of liquid
is predetermined taking into account the maximum variation of weight between blood
donations, so that, at the end of the second stage, the weights in the various separation
cells 40 are substantially equal and the rotor is substantially balanced, whatever
the specific weights of the separation bags 1 that are loaded in the separation cells
40. Note that this does not imply that the internal cavity 43 of the separation cells
40 should be filled up at the end of the balancing stage. For the purpose of balancing
the rotor, it suffices that there is enough hydraulic liquid in the separation cells
40 for equalizing the weights therein, and it does not matter if an empty space remains
in each separation cell 40 (the size of this empty space essentially depends on the
volume of the internal cavity 43 of a separation cell 40 and the average volume of
a blood donation). Because the hydraulic chambers 51 are interconnected, the distribution
of the overall volume of hydraulic liquid between the separations chambers 40 simply
results from the rotation of the rotor. When the weights of the separation bags 1
are the same, the distribution of the hydraulic liquid is even. When they are not,
the distribution of the hydraulic liquid is uneven, and the smaller the weight of
a specific separation bag 1, the larger the volume of the hydraulic fluid in the associated
hydraulic chamber 51.
Third stage (first protocol): the blood within the separation bags 1 is sedimented to a desired level.
[0056] At the onset of this stage, all pinch valve members 70, 71 are closed. The rotor
is rotated at a second centrifugation speed (high sedimentation speed or "hard spin")
for a predetermined period of time that is so selected that, whatever the hematocrit
of the blood in the separation bags 1, the blood sediments in each of the separation
bag 1 at the end of the selected period to a point where the hematocrit of the outer
red blood cell layer is about 90 and the inner plasma layer does not substantially
contain anymore cells, the platelets and the white blood cells forming then an intermediary
layer between the red blood cell layer and the plasma layer.
Fourth stage (first protocol): a plasma component is transferred into the plasma component bags 2.
[0057] At the onset of this stage, the rotation speed is decreased to a third centrifugation
speed, the four first pinch valve members 70 controlling access to the plasma component
bags 2 are opened, and the pumping station 60 is actuated so as to pump hydraulic
liquid at a first constant flow rate into the hydraulic chambers 51 and consequently
squeeze the separation bags 1 and cause the transfer of plasma into the plasma component
bags 2.
[0058] When blood cells are detected by the bag sensor 73 in the separation cell 40 in which
this detection occurs first, the pumping station 60 is stopped and the corresponding
first pinch valve member 70 is closed, either immediately of after a predetermined
amount of time selected in view of the volume of plasma that it is desirable in the
buffy coat component to be expressed in a next stage.
[0059] Following the closure of the first (first) pinch valve member 70 (i.e. the first
pinch valve of the group of first pinch valve members 70) to close, the pumping station
60 is actuated anew so as to pump hydraulic liquid at a second, lower, flow rate into
the hydraulic chambers 51 and consequently squeeze the three separation bags 1 whose
outlet is not closed by the corresponding first pinch valve members 70.
[0060] When blood cells are detected by the bag sensor 73 in the separation cell 40 in which
this detection occurs second, the pumping station 60 is stopped and the corresponding
first pinch valve member 70 is closed (same timing as for the closing of the first
(first) pinch valve member to close).
[0061] Following the closure of the second (first) pinch valve member 70 to close, the pumping
station 60 is actuated anew so as to pump hydraulic liquid at the second flow rate
into the hydraulic chambers 51 and consequently squeeze the two separation bags 1
whose outlet is not closed by the corresponding first pinch valve members 70.
[0062] When blood cells are detected by the bag sensor 73 in the separation cell 40 in which
this detection occurs third, the pumping station 60 is stopped and the corresponding
first pinch valve member 70 is closed (same timing as for the closing of the first
(first) pinch valve member to close).
[0063] Following the closure of the third (first) pinch valve member 70 to close, the pumping
station 60 is actuated anew so as to pump hydraulic liquid at the second flow rate
into the hydraulic chambers 51 and consequently squeeze the separation bag 1 whose
outlet is not yet closed by the corresponding first pinch valve member 70.
[0064] When blood cells are detected by the bag sensor 73 in the separation cell 40 in which
this detection occurs last, the pumping station 60 is stopped and the corresponding
first pinch valve member 70 is closed (same timing as for the closing of the first
pinch valve member to close).
[0065] In the plasma component transfer process described above, the transfer of the four
plasma components starts at the same time, run in part simultaneously and stop independently
of each other upon the occurrence of a specific event in each separation bag (detection
of blood cells by the bag sensor).
[0066] As a variant, when the second flow rate is sufficiently low and the closing of the
first pinch valve member 70 occurs almost simultaneously with the detection of blood
cells in the separation bags, then the pumping station can be continuously actuated
during the fourth stage.
[0067] The fourth stage ends when the four first pinch valve members 70 are closed.
Fifth stage (first protocol): a buffy coat component is transferred into the buffy coat component bags 15.
[0068] The control unit 90 is programmed to start the fifth stage after the four first pinch
valve members 70 are closed, upon receiving information from the last bag sensor 73
to detect blood cells.
[0069] At the onset of this stage, the rotation speed remains the same (third centrifugation
speed), a first of the four second pinch valve members 71 controlling access to the
buffy coat component bags 15 is opened, and the pumping station 60 is actuated so
as to pump hydraulic liquid at a third constant flow rate into the hydraulic chambers
51 and consequently squeeze the separation bag 1 in the separation cell 40 associated
with the opened second pinch valve members 71 and cause the transfer of the buffy
coat component into the buffy coat component bag 2 connected to this separation bag
1.
[0070] After a predetermined period of time after blood cells are detected by the tube sensor
74 in the separation cell 40 associated with the opened second pinch valve member
71, the pumping station 60 is stopped and the second pinch valve member 71 is closed.
[0071] After the first (second) pinch valve member 71 has closed (i.e. the first pinch valve
of the group of second pinch valve members 71), a second (second) pinch valve member
71 is opened, and a second buffy coat component is transferred into a buffy coat component
bag 2, in the same way as above.
[0072] The same process is successively carried out to transfer the buffy coat component
from the two remaining separation bags 1 into the buffy coat component bag 2 connected
thereto.
[0073] In the buffy coat component transfer process described above, the transfers of the
four buffy coat components are successive, and the order of succession is predetermined.
However, each of the second, third and four transfers starts following the occurrence
of a specific event at the end of the previous transfer (detection of blood cells
by the tube sensor 74 or closing of the second valve member 71).
[0074] As a variant, when the third flow rate is sufficiently low and the closing of the
second pinch valve members 71 occurs almost simultaneously with the detection of blood
cells in the tubes 4, then the pumping station can be actuated continuously during
the fourth stage.
[0075] As a variant, the control unit 90 is programmed to start the fifth stage after a
predetermined period of time after receiving information from the first (or the second
or the third) bag sensor 73 to detect blood cells. The period of time is statistically
or empirically determined so that, whatever the event from which it starts running
(detection of the blood cells by either one of the first, second, and third bag sensor
73 to detect blood cells); the four first pinch valve members 70 are closed when it
is over.
[0076] The fifth stage ends when the four second pinch valve members 71 are closed.
Sixth stage (first protocol): the centrifugation process is ended.
[0077] The control unit 90 is programmed to start the sixth stage after the four (second)
pinch valve members 71 are closed, upon receiving information from the last tube sensor
74 to detect blood cells.
[0078] The rotation speed of the rotor is decreased until the rotor stops, the pumping station
60 is actuated so as to pump the hydraulic liquid from the hydraulic chambers 51 at
a high flow rate until the hydraulic chambers 51 are empty, and the first and second
pinch valve members 70, 71 are actuated so as to seal and cut the tubes 17, 18. The
blood cells remain in the separation bags 1.
[0079] When the fifth stage is completed, the four bag sets are removed from the separation
apparatus and each bag set is separately handled manually.
[0080] The breakable stopper 10 blocking the communication between the separation bag 1
and the tube 6 connected thereto is broken, as well as the breakable stopper 14 blocking
the communication between the second satellite bag 3 and the tube 6. The storage solution
contained in the second satellite bag 3 is allowed to flow by gravity through the
leuko-reduction filter 13 and into the separation bag 1, where it is mixed with the
red blood cells so as to lower the viscosity thereof. The content of the separation
bag 1 is then allowed to flow by gravity through the filter 13 and into the second
satellite bag 3. The white blood cells are trapped by the filter 13, so that substantially
only red blood cells are collected into the second satellite bag 3.
[0081] As a variant, the control unit 90 is programmed to start the sixth stage after a
predetermined period of time after receiving information from the first (or the second
or the third) tube sensor 74 to detect blood cells. The period of time is statistically
or empirically determined so that, whatever the event from which it starts running
(detection of the blood cells by either one of the first, second, and third tube sensor
74 to detect blood cells), the four second pinch valve members 71 are closed when
it is over.
[0082] According to a
second separation protocol, four discrete volumes of blood are separated into a plasma component, a platelet
component and a red blood cell component. Each volume of blood is contained in a separation
bag 1 of a bag set represented in figure 2, in which it has previously been collected
from a donor using the collection tube 5. After the blood collection, the collection
tube 5 has been sealed and cut close to the separation bag 1. Typically, the volumes
of blood are not the same in the four separation bags 1, which, consequently, have
slightly different weights. Also, typically, the hematocrit varies from one separation
bag 1 to another one.
First stage (second protocol): setting the four bag sets in the separation apparatus
[0083] This stage is identical to the first stage of the first protocol.
Second stage (second protocol): balancing the rotor in order to compensate for the difference in weights of the separation
bags
[0084] This stage is identical to the second stage of the first protocol.
Third stage (second protocol): the blood within the separation bags 1 is sedimented to a desired level.
[0085] This stage is identical to the third stage of the first protocol.
Fourth stage (second protocol): a first, larger, portion of plasma is transferred into the plasma bags 2, while a
second, smaller, portion of plasma remains in the separation bags 1.
[0086] This stage is substantially the same as the fourth stage of the first protocol. However,
the expression of plasma from each separation bag 1 into the attached plasma component
bag 2 is stopped immediately after detection of blood cells by the corresponding bag
sensor 73, so that the volume of plasma remaining in the separation bag 1 is large
enough to allow the platelets to be re-suspended therein.
Fifth stage (second protocol): a platelet component is prepared in the separation bag 1.
[0087] At the onset of this fifth stage, the first and second valve members 70, 71 are closed.
The rotor is stopped and the pumping station 60 is actuated so as to pump a volume
of hydraulic liquid from the hydraulic chambers 51 at a high flow rate. The rotor
is then controlled so as to oscillate back and forth around the rotation axis 31 for
a determined period of time, at the end of which the cells in the separation bags
1 are substantially suspended in plasma. The rotor is then set in motion again by
the centrifuge motor 36 so that its rotation speed increases steadily until it reaches
a fourth centrifugation speed (low sedimentation speed or "soft spin''). The rotor
is rotated at the fourth rotation speed for a predetermined period of time that is
selected so that the blood sediments in the separation bags 1 at the end of the selected
period to a point where the separation bags 1 exhibit an outer layer comprising packed
red blood cells and an inner annular layer substantially comprising platelets suspended
in plasma.
Sixth stage (second protocol): a platelet component is transferred into the platelet bags 15.
[0088] This stage is substantially the same as the fifth stage of the first protocol (buffy
coat expression).
Seventh stage (second protocol): the centrifugation process is ended.
[0089] This stage is substantially the same as the sixth stage of the first protocol.
[0090] Figures 13 to 18 show a third embodiment of a separation apparatus for four discrete
volumes of a composite liquid.
[0091] The separation apparatus of figure 13 to 18 is particularly adapted to the separation
of a composite fluid in two components, for example the separation of whole blood
into a cell component (red blood cells, white cells and platelets) and a plasma component
substantiaiiy devoid of cells or the separation of whole blood into a cell component
(red blood cells, white cells and a small amount of platelets) and a plasma component
containing a large amount of platelets in suspension.
[0092] The main differences between the first separation apparatus shown in figures 4 and
5 and the third separation apparatus shown in figures 13 to 18 are as follows:
- The shape of the separation cells 100 of the third separation apparatus is different
from the shape of the separation cells 40 of the first separation apparatus.
- Each of the separation cells 100 of the third separation apparatus is associated with
one pinch valve member 70 and one tube sensor 74.
- The third separation apparatus does not comprise a pumping station for pumping a hydraulic
liquid in and out of the hydraulic chambers of the separation cells 100.
[0093] In more details, a separation cell 100 for the third separation apparatus comprises
a container 101 having the general shape of a rectangular parallelepiped. The cavity
(also referred to as the "separation compartment'') of the container 101, which has
also the general shape of a rectangular parallelepiped, is so dimensioned as to loosely
accommodate a separation bag 1 full of liquid, of the type shown in figure 2. The
separation cell 100 further comprises an elastic diaphragm 110, which defines within
the cavity of the container 101 a first chamber 102 for receiving a separation bag
1, and a second hydraulic chamber 103 that is connected to the peripheral manifold
52, through an inlet aperture 104 close to the bottom of the container 101. The separation
cell 100 further comprises a lid having two flaps 105, 106 that are hinged to the
longer parallel sides of the opening of the container 101. The two flaps 105, 106
can be locked in a closed position by a locking means (not shown). The separation
cell 100 further comprises a securing means for securing a separation bag 1 within
the separation cell 100. The bag securing means comprises two pins 107 and two corresponding
recesses 108 that respectively protrude or open on the edges of the flaps 105, 106
that face each other when the lid is closed. The two pins 107 are so spaced apart
and dimensioned as to fit into the two holes 8 in the upper corner of a separation
bag 1. The two flaps 105, 106 also comprise on their facing edges three semi-cylindrical
holes 109 for accommodating the proximal end of three tubes 4, 5, 6 embedded in the
upper area of a separation bag 1. The outer flap 106 includes a cavity facing the
median semi-cylindrical hole 109, for containing the bag sensor 74.
[0094] As shown in figures 15 to 18, the diaphragm 110 comprises a flat rectangular socket
111 almost as wide as a separation cell 100. The diaphragm 110 further comprises a
large, rectangular, connecting portion 112 extending around the mouth of the socket
111, perpendicularly to the socket 111 when the diaphragm 110 is not deformed by a
separation bag 1 and it is held in an upright position (figure 15). The socket 111
is connected to the connecting portion 112 along the longitudinal median axis thereof.
The connecting portion 112 has a surface slightly larger than a transversal cross-section
of the cavity of the container 101. The diaphragm 110 is tightly attached to the top
of the container 101 by a peripheral area of the connecting portion 112. The diaphragm
110 is made of an elastic and deformable elastomeric material so selected that the
diaphragm 110 conforms very closely the shape of a separation bag 1 before and during
centrifugation and as shown in figures 16 to 18.
[0095] As mentioned above, the separation apparatus shown in figure 13 does not comprise
a pumping station for pumping a hydraulic fluid in and out of the hydraulic chambers
103. Instead, it comprises a reservoir 120 for hydraulic liquid, which is fixed with
respect to the rotor, and which is directly connected to the rotor duct 56 by a conduit
121 and a rotary seal 122. The conduit 121 is fitted with a valve 123. The reservoir
120 is secured to a frame of the separation apparatus so as to be lower than the four
separation cells 100. When the separation apparatus is used for separating red blood
cells from plasma (with or without suspended platelets), the density of the hydraulic
liquid is selected, for reasons explained below, so as to be between the density of
packed red blood cells and the density of plasma.
[0096] The component transferring means of the third separation apparatus essentially comprises
the reservoir 120 that is directly connected to the rotor duct 56 by the rotary seal
122, the hydraulic chambers 103, and the motor 36 that drives the rotor in rotation.
When the valve 123 is opened and the rotation speed of the rotor reaches a determined
threshold, which depends on the height between the reservoir 120 and the separation
cells 100 and the distance between the rotation axis 31 and the separation cells 100,
then the hydraulic liquid flows from the reservoir 120 into the hydraulic chambers
103 so as to fill up the hydraulic chamber 103 and squeeze the separation bags 1 therein,
whatever the volume/weight of the separation bags 1. The speed threshold is substantially
below the rotation speed at which the rotor is rotated for separating blood components
("high spin" as well as "soft spin). The transfer of a separated component from a
separation bag 1 into a satellite bag 2 is then controlled by the opening/closing
of the pinch valve member 70 in which the tube 4 connecting the two bags is inserted.
[0097] The first balancing means of the third separation apparatus essentially comprises
the reservoir 120 that is directly connected to the rotor duct 56 through the rotary
seal 122, the hydraulic chambers 103, the motor 36 that drives the rotor in rotation,
and the valve 123. At the onset of a separation process, the valve 123 is opened for
a predetermined period of time so as to allow the transfer, in the interconnected
hydraulic chambers 103, of a predetermined volume of hydraulic liquid that is so selected
as to balance the rotor in the most unbalanced situation. For whole blood, the determination
of this balancing volume takes into account the maximum difference in volume between
two blood donations, and the maximum difference in hematocrit (i.e. in density) between
two blood donations.
[0098] A variant of the third embodiment of a separation apparatus does not comprise a valve
123 on the conduit 121 connecting the reservoir 120 to the rotor duct 56. As a result,
when the threshold speed is reached, the hydraulic liquid is pumped from the reservoir
120 into the hydraulic chambers 103 until the pressure that is building up within
the separation cells 100 prevents further pumping. The filling up of the space available
in the separation cells 100 with hydraulic liquid might not however result in an optimal
balance of the rotor depending, in particular, on the difference in weight of the
separation bags 1, of their volume, and of the density of the hydraulic liquid.
[0099] The operation of the third separation apparatus, in accordance to a third illustrative
separation protocol, will be described now.
[0100] According to a
third separation protocol, four discrete volumes of blood are separated into a plasma component (including or
not including a substantial amount of platelets) and a blood cell component (including
platelets, or residual platelets, white blood cells and red blood cells). Each volume
of blood is contained in a separation bag 1 of a bag set represented in figure 1,
in which it has previously been collected from a donor using the collection tube 5.
After the blood collection, the collection tube 5 has been sealed and cut close to
the separation bag 1. Typically, the volumes of blood are not the same in the four
separation bags 1 and the hematocrit varies from one separation bag 1 to another one.
As a result, the separation bags have slightly different weights.
First stage (third protocol): setting the four bag sets in the separation apparatus
[0101] Four separation bags 1 are inserted into the socket 111 of a diaphragm 110 within
the four separation cells 100 as shown in figure 16. The two flaps 105, 106 of the
lids of the separation cells 100 are closed and consequently secure the top of the
separation bags 1 to the separation cells 100. The tube sensors 74 embedded in the
outer flap 106 of the lids now face the proximal end of the tubes 4 connecting the
separation bags 1 to the plasma component bags 2. The tubes 4 are inserted in the
groove 72 of the pinch valve members 70. The four plasma component bags 2, the four
red blood cell component bags 3 and the four leuko-reduction filters 13 are inserted
in the central compartment 34 of the rotor. The pinch valve members 70 are closed
and the breakable stoppers 9 in the tubes 4 connected to the plasma component bags
2 are manually broken.
Second stage (third protocol): balancing the rotor in order to compensate for the difference in weights of the separation
bags
[0102] At the onset of this second stage, the pinch valve members 70, in which the tubes
4 are engaged, are closed. The valve 123 on the conduit connecting the reservoir 120
to the rotor duct 56 is opened. The rotor is set in motion by the centrifuge motor
36 and its rotation speed increases steadily until it rotates at a predetermined sedimentation
speed. Before it rotates at the sedimentation speed, the rotor reaches a threshold
speed at which its rotation causes the pumping of hydraulic liquid from the reservoir
120 into the interconnected hydraulic chambers 103 of the separation cells 100. The
valve is closed 123 after a predetermined amount of hydraulic fluid sufficient for
balancing the rotor has been transferred in the hydraulic chambers 103. Because the
hydraulic chambers 103 are interconnected by the peripheral manifold 52, the hydraulic
liquid gets automatically distributed in the separation cells 100 so as to balance
the rotor.
[0103] When the weights of the separation bags 1 are the same, the distribution of the hydraulic
liquid is even. When they are not, the distribution of the hydraulic liquid is uneven,
and the smaller the weight of blood in a specific separation bag 1, the larger the
volume of the hydraulic fluid in the associated hydraulic chamber 103.
Third stage (third protocol): the blood within the separation bags 1 is sedimented to a desired level.
[0104] When it is desired to separate a plasma component containing a large amount of suspended
platelets ("platelet rich plasma'') and a cell component mainly containing red blood
cells and white blood cells, the rotor is rotated at a first sedimentation speed (about
2000 RPM, usually referred to as "soft spin'').
When it is desired to separate a plasma component substantially devoid of cells ("platelet
poor plasma'') and a cell component containing red blood cells, white blood cells
and platelets, the rotor is rotated at a second sedimentation speed (about 3200 RPM,
usually referred to as "hard spin'').
The rotor is rotated at the selected sedimentation speed for a predetermined period
of time that is selected so that, whatever the hematocrit of the blood in the separation
bags 1, the blood sediments at the desired level in each of the separation bag 1 at
the end of the selected period. Since, as mentioned above, the density of the hydraulic
liquid is selected so as to be between the density of the packed red cells and the
density of the plasma, the separation bag 1 will take a hour-glass shape at the end
of the sedimentation stage, as shown in figure 17.
Fourth stage (third protocol): a plasma component is transferred into the satellite bags 2.
[0105] At the onset of this stage, the four pinch valve members 70 controlling the access
to the plasma component bags 2 are opened. This causes a decrease in pressure within
the separation cells 100 and hydraulic liquid starts flowing again into the hydraulic
chambers 103. The raising volume of hydraulic fluid in the hydraulic chamber 103 squeezes
the separation bags 1 and causes the transfer of the plasma component into the first
satellite bags 2. Because the hydraulic liquid has a lower density than the density
of the packed red blood cells, the red blood cells remain at the bottom of the separation
cell 100 and the separation bags 1 progressively collapse above the red cells as shown
in figure 18.
[0106] When each tube sensor 74 detects blood cells, then the associated pinch valve member
70 is closed. When the volumes of blood in the four separation bags 1 are different,
and/or the hematocrit of the blood in the four separation bags 1 is different (which
will be generally the case), then the four pinch valve members 70 close one after
the other.
[0107] The fourth stage end when the four pinch valve members 70 are closed.
Fifth stage (third protocol): the centrifugation process is ended.
[0108] When the last pinch valve member 70 closes, the rotation speed of the rotor is decreased
until the rotor stops. The hydraulic liquid simultaneously drains from the hydraulic
chambers 103 into the reservoir 120. The red blood cells and the white blood cells
remain in the separation bag 1 (as well as the platelets when the plasma component
collected is a "platelet poor plasma'').
[0109] When the fifth stage is completed, the four bag sets are removed from the separation
apparatus and each bag set is separately handled manually.
The breakable stopper 10 blocking the communication between the separation bag 1 and
the tube 6 connected thereto is broken, as well as the breakable stopper 14 blocking
the communication between the second satellite bag 3 and the tube 6. The storage solution
contained in the second satellite bag 3 is allowed to flow by gravity through the
filter 13 and into the separation bag 1, where it is mixed with the blood cells so
as to lower the viscosity thereof. The content of the separation bag 1 is then allowed
to flow by gravity through the filter 13 and into the second satellite bag 3. The
white blood cells and the platelets are trapped by the filter 13, so that substantially
only red blood cells are collected into the second satellite bag 3.
[0110] Figure 19 shows a fourth embodiment of a separation apparatus for four discrete volumes
of a composite liquid.
[0111] The main differences between the third separation apparatus shown in figures 13 to
18 and the fourth separation apparatus shown in figure 19 are as follows:
- The fourth separation apparatus does not comprise a fixed reservoir directly connected
to the separation chambers, via a conduit, a rotary seal and a rotor duct;
- The fourth separation apparatus comprises a hydraulic liquid reservoir 130 that is
mounted on the rotor.
[0112] The rotor of the apparatus of figure 19 comprises:
- A central container 34 for satellite bags, having the shape of a cylindrical bucket;
- A turntable 35 having a frusto-conical wall supporting four separation cells 100 at
an angle with respect to the rotation axis 31; the turntable 35 is connected by its
smaller diameter section to an upper rim of the central container 34 so as to flare
underneath the rim of the central container 34;
- A reservoir 130 for hydraulic liquid, which comprises a circular bottom wall 131 and
frusto-conical wall 132 connected by its smaller diameter section to the circular
bottom wall 131 and by its larger diameter section to the lower rim of the turntable
35 (i.e. the section of the turntable having the larger diameter). In other words,
the interior of the reservoir 130 has a compiex geometrical volume that is symmetrical
with respect to the rotation axis 31 and that is defined by the outside surface or
the central container 34, the inner surface of the turntable 35, the inner surface
of the frusto-conical wall 132 of the reservoir, and the inner surface of the bottom
wall 131 of the reservoir.
- A rotor shaft 32, which is connected to the bottom wall of the reservoir 130.
[0113] The reservoir 130 is fluidly connected to the hydraulic chamber 103 of each separation
cell 100 by an outlet aperture 133 through the turntable 35 that coincides with the
inlet aperture 104 of the hydraulic chambers 103. As shown, the outlet apertures 133
are located the farthest from the rotation axis 31. With this arrangement, the hydraulic
liquid flows from the reservoir 130 into the hydraulic chambers 103 of the separation
cells 100 under centrifugal forces as soon as the rotor starts rotating. When the
separation apparatus is to be used for separating red blood cells from plasma (with
or without suspended platelets), the density of the hydraulic fluid is selected so
as to be between the density of pack red cells and the density of plasma.
[0114] In this fourth embodiment of a separation apparatus, the component transferring means
essentially comprise the reservoir 130, the hydraulic chambers 103 and the motor 36
that drives the rotor in rotation. When the rotor rotates, the hydraulic liquid drains
from the reservoir 130 into the hydraulic chambers 103 under centrifugal forces and
presses the separation bags 1 within the separation cell 100 through the elastic diaphragm
110. The transfer of a separated component from a separation bag 1 into a satellite
bag 2 is controlled by the opening/closing of the pinch valve member 70 in which the
tube 4 connecting the two bags is inserted.
[0115] The first balancing means essentially comprise the reservoir 130, the hydraulic chambers
103 and the motor 36 that drives the rotor in rotation. As soon as the rotor starts
rotating, hydraulic fluid flows from the reservoir 130 into the hydraulic chambers
103 until it completely fills up the space let vacant in the separation cells 100
by the separation bags 1, which happens before the rotor has reach the desired sedimentation
speed. The filling up of the space available in the separation cells 100 with hydraulic
liquid might not however result in an optimal balance of the rotor depending, in particular,
on the difference in weight of the separation bags 1, on their volume, and on the
density of the hydraulic liquid.
[0116] It will be apparent to those skilled in the art that various modifications can be
made to the apparatus and method described herein. Thus, it should be understood that
the invention is not limited to the subject matter discussed in the specification.
Rather, the present invention is intended to cover modifications and variations.
1. A method for separating at least two discrete volumes of a composite liquid into at
least a first component and a second component, comprising:
- enclosing in at least two separation cells (40; 100) mounted on a rotor (32, 34,
35) at least two separation bags (1) containing two discrete volumes of a composite
liquid respectively;
- storing in a container (34; 341, 342, 343, 344) included in the rotor (32, 34, 35)
at least two first satellite bags (2) connected to the at least two separation bags
(1) respectively;
- rotating the rotor (32, 34, 35); and
- transferring a volume of hydraulic liquid into at least two interconnected expandable
hydraulic chambers (51; 103) located in the at least two separation cells (40; 100)
respectively, whereby the hydraulic liquid gets distributed under centrifugation forces
in the at least two interconnected hydraulic chambers (51; 103) so as to substantially
balance the rotor (32, 34, 35).
2. A method according to claim 1, wherein transferring a volume of hydraulic liquid into
the at least two interconnected hydraulic chambers (51; 103) comprises transferring
a predetermined volume of hydraulic liquid.
3. A method according to one of the claims 1 and 2, wherein transferring a volume of
hydraulic liquid into the at least two interconnected hydraulic chambers (51; 103)
comprises pumping hydraulic liquid into the at least two interconnected hydraulic
chambers (51; 103).
4. A method according to one of the claims 1 and 2, wherein transferring a volume of
hydraulic liquid into the at least two interconnected hydraulic chambers (51; 103)
comprises connecting a source of hydraulic liquid (120, 130) to the at least two interconnected
hydraulic chambers (51; 103) so that a rotation of the rotor (32, 34, 35) causes hydraulic
liquid to be transferred from the source of hydraulic liquid into the at least two
interconnected hydraulic chambers (51; 103).
5. A method according to one of the claims 1 to 4, wherein rotating the rotor (32, 34,
35) comprises rotating the rotor (32, 34, 35) at a sedimentation speed at which the
at least first and a second components sediment in each of the separation bags (1).
6. A method according to claim 5, further comprising:
- transferring a first separated component from the at least two separation bags (1)
into the at least two first satellite bags (2) connected thereto respectively; and
- balancing any unbalance of the rotor (32, 34, 35) caused by the transfer of the
first separated component into the at least two first satellite bags (2).
7. A method according to claim 6, wherein balancing any unbalance of the rotor (32, 34,
35) caused by the transfer of the first separated component into the at least two
first satellite component bags (2) comprises respectively storing the at least two
first satellite bags in the container (34; 341, 342, 343, 344) against at least two
interconnected flexible pouches (80; 81, 82, 83, 84) containing a volume of a liquid
secured to a wall of the container (34; 341, 342, 343, 344), whereby the at least
two first satellite bags press against the at least two pouches (80; 81, 82, 83, 84)
under centrifugation forces and distribute the volume of liquid in the at least two
pouches (80; 81, 82, 83, 84) so as to balance the rotor (32, 34, 35).
8. A method according to one of the claims 6 and 7, wherein transferring a first separated
component from the at least two separation bags (1) into the at least two first satellite
bags (2) connected thereto respectively comprises:
- squeezing the at least two separation bags (1) within the at least two separation
cells (40; 100) so as to cause a transfer of at least one fraction of the first component
into the at least two first satellite bags (2) connected thereto;
- detecting a characteristic of a component at a first determined location in each
separation bag (1);
- stopping transferring the at least one fraction of the first component from each
separation bag (1) into the first satellite bag (2) connected thereto, upon detection
of the characteristic of a component at the first determined location.
9. A method according to claim 8, further comprising changing a speed of the rotor (32,
34, 35) after detecting a characteristic of a component at the first determined location
in the separation bag (1) in which such detection occurs last.
10. A method according to claim 8, further comprising changing a speed of the rotor (32,
34, 35) after a predetermined period of time after detecting a characteristic of a
component at the first determined location in one of the at least two separation bags
(1).
11. A method according to one of the claims 6 to 8, further comprising:
- transferring a second separated component from the at least two separation bags
(1) into at least two second satellite bags (15) connected thereto respectively; and
- balancing any unbalance of the rotor (32, 34, 35) caused by the transfer of the
second separated component into the at least two second satellite bags (15).
12. A method according to claim 11, wherein balancing any unbalance of the rotor (32,
34, 35) caused by the transfer of the second separated component into the at least
two second satellite component bags (15) comprises respectively storing the at least
two second satellite bags in the container (34; 341, 342, 343, 344) against the at
least two interconnected flexible pouches containing a volume of a liquid secured
to a wall of the container (34; 341, 342, 343, 344), whereby the at least two second
satellite bags press against the at least two pouches (80; 81, 82, 83, 84) under centrifugation
forces and distribute the volume of liquid in the at least two pouches (80; 81, 82,
83, 84) so as to balance the rotor (32, 34, 35).
13. A method according to one of the claims 11 and 12, wherein transferring a second separated
component from the at least two separation bags (1) into the at least two second satellite
bags (15) connected thereto respectively comprises:
- squeezing one of the at least two separation bags (1) within one of the at least
two separation cells (40; 100) so as to cause a transfer of the second component into
the second satellite bag (15) connected thereto;
- detecting a characteristic of a component at a second determined location in either
the squeezed separation bag (1) or a tube (4) connecting the squeezed separation bag
(1) to a second satellite bag (15);
- stopping squeezing the squeezed separation bag (1) upon detection of the characteristic
of a component at the second determined location; and
- successively repeating the above steps with each separation bag (1) of the at least
two separation bags (1).
14. A method according to claim 13, further comprising stopping rotating the rotor (32,
34, 35) after detecting a characteristic of a component at the second determined location
in the separation bag (1) or the tube (4) connected thereto in which such detection
occurs last.
15. A method according to claim 13, further comprising stopping rotating the rotor (32,
34, 35) after a predetermined period of time after detecting a characteristic of a
component at the second determined location in one of the at least two separation
bags (1) or the tube (4) connected thereto.
16. An apparatus for separating at least two discrete volumes of a composite liquid into
at least a first component and a second component, whereby the at least two discrete
volumes can have different weights, the apparatus comprising a centrifuge comprising:
- a rotor (32, 34, 35) having a rotation axis (31), comprising
- at least two separation cells (40; 100), each for containing a separation bag (1)
containing a volume of composite liquid; and
- a first balancing means for balancing the rotor (32, 34, 35) when the respective
weights of the at least two separation bags (1) in the at least two separation cells
(40; 100) are different, comprising:
- at least two expandable hydraulic chambers (51; 103) within the at least two separation
cells (40; 100) respectively, wherein the at least two hydraulic chambers (51; 103)
are fluidly interconnected;
- a source of hydraulic liquid (66; 120; 130) fluidly connected to the at least two
hydraulic chambers (51; 103); and
- a liquid transferring means for transferring a volume of hydraulic liquid from the
hydraulic liquid source into the at least two interconnected hydraulic chambers (51;
103) so as to substantially balance the rotor (32, 34, 35) when two separation bags
(1) respectively contained in the at least two different separation cells (40; 100)
have different weights.
17. An apparatus according to claim 16, further comprising a control unit (90) programmed
for causing the liquid transferring means to transfer a predetermined volume of hydraulic
liquid from the hydraulic liquid source into the at least two interconnected hydraulic
chambers (51; 103), wherein the predetermined volume of hydraulic liquid is selected
so as to substantially balance the rotor (32, 34, 35) whatever the weights of two
separation bags (1) respectively contained in the at least two different separation
cells (40; 100).
18. An apparatus according to one of the claims 16 and 17, wherein the liquid transferring
means comprises a pumping means (60) for pumping a volume of hydraulic fluid into
the at least two interconnected hydraulic chambers (51).
19. An apparatus according to one of the claims 16 to 18, wherein the source of hydraulic
liquid (66; 120) is fixed with respect to the rotor (32, 34, 35) and is fluidly connected
to the at least two hydraulic chambers (51; 103) through a rotary seal (69; 122).
20. An apparatus according to claim 16, wherein the liquid transferring means comprises
a motor (36) for driving the rotor (32, 34, 35) in rotation, and wherein the source
of hydraulic liquid (120) is fixed with respect to the rotor (32, 34, 35), below the
at least two separation cells (100), and is fluidly connected to the hydraulic chambers
(103) through a rotary seal (122), whereby a rotation of the rotor (32, 34, 35) causes
the volume of hydraulic liquid to be transferred from the hydraulic liquid source
(120) into the hydraulic chambers (103).
21. An apparatus according to claim 20, wherein the first balancing means further comprises
a valve (123) fitted on a conduit (121) between the source of hydraulic liquid (120)
and the rotary seal (122), for controlling a transfer into the hydraulic chambers
(103) of a predetermined volume of hydraulic liquid for balancing the rotor (32, 34,
35).
22. An apparatus according to one of the claims 16 to 21, wherein the at least two hydraulic
chambers (51; 103) are interconnected by a circular conduit (52) centered on the rotation
axis (31), and the circular conduit (52) is connected to each hydraulic chamber (51;
103) to an area thereof that is closer to a periphery of the rotor (32, 34, 35) than
to the rotation axis (31).
23. An apparatus according to claim 16, wherein the liquid transferring means comprises
a motor (36) for driving the rotor (32, 34, 35) in rotation, and wherein the source
of hydraulic liquid comprises a reservoir (130) for hydraulic liquid that is mounted
on the rotor (32, 34, 35) and is so designed and fluidly connected to the at least
two hydraulic chambers (103) that a rotation of the rotor (32, 34, 35) causes a transfer
of hydraulic liquid from the reservoir into the at least two hydraulic chambers (103).
24. An apparatus according to claim 23, wherein the reservoir (130) comprises a housing
defining an internal volume that is symmetrical with respect to the rotation axis
(31) and a circular inner area that is the farthest to the rotation axis (31), and
wherein the at least two hydraulic chambers (103) are in fluid communication with
this circular area of the reservoir (103).
25. An apparatus according to one of the claims 16 to 24, further comprising:
- a storage means (34; 341, 342, 343, 344) included in the rotor (32, 34, 35) for
storing at least two satellite bags (2; 3; 15) respectively connected to at least
two separation bags (1) contained in the at least two separation cells (40; 100);
and
- a component transferring means for transferring at least one separated component
from each separation bag (1) into a satellite bag connected thereto (2; 3; 15).
26. An apparatus according to claim 25, wherein the component transferring means comprises
a pumping means (60) for pumping hydraulic liquid from the source of hydraulic liquid
(66) into the at least two interconnected hydraulic chambers (51) so as to squeeze
the at least two separation bags (1) within the at least two separation cells (40)
and to cause a component separated therein to flow into a satellite bag (2, 3, 15)
connected to each separation bag (1).
27. An apparatus according to claim 25, wherein the source of hydraulic liquid (120) is
fixed with respect to the rotor (32, 34, 35), below the at least two separation cells
(100), and is fluidly connected to the at least two hydraulic chambers (103) through
a rotary seal (122), and wherein the component transferring means comprises:
- a motor (36) for driving the rotor (32, 34, 35) in rotation; and
- at least one valve member (70, 71) associated with each separation cell (40; 100)
for selectively allowing or blocking a flow of fluid between a separation bag (1)
and a satellite bag (2; 3; 15),
whereby a rotation of the rotor (32, 34, 35) causes hydraulic liquid to be transferred
from the hydraulic liquid source (120) into the at least two hydraulic chambers (103)
and to squeeze the at least two separation bags (1) within the at least two separation
cells (100), which causes a component separated in a separation bag (1) to flow into
a satellite bag (2; 3; 15) connected thereto when the valve member (70, 71) for allowing
or blocking a flow of fluid between the separation bag (1) and the satellite bag (2;
3; 15) is open.
28. An apparatus according to claim 25, wherein the source of hydraulic liquid (130) comprises
a reservoir for hydraulic liquid that is mounted on the rotor (32, 34, 35) and is
fluidly connected to the at least two hydraulic chambers (103), and wherein the component
transferring means comprises:
- a motor (36) for driving the rotor (32, 34, 35) in rotation; and
- at least one valve member (70, 71) associated with each separation cell (100) for
selectively allowing or blocking a flow of fluid between a separation bag (1) and
a satellite bag (2; 3; 15),
whereby a rotation of the rotor (32, 34, 35) causes hydraulic liquid to be transferred
from the reservoir into the at least two hydraulic chambers (103) and to squeeze the
at least two separation bags (1) within the at least two separation cells (100), which
causes a component separated in a separation bag (1) to flow into a satellite bag
(2; 3; 15) connected thereto when the valve member (70, 71) for allowing or blocking
a flow of fluid between the separation bag (1) and the satellite bag (2; 3; 15) is
open.
29. An apparatus according to one of the claims 25 to 28, further comprising a second
balancing means (80; 81, 82, 83, 84) for balancing the rotor (32, 34, 35) when the
at least two satellite bags (2; 3; 15) stored in the storing means (35; 341, 342,
343, 344) cause an unbalance of the rotor (32, 34, 35).
30. An apparatus according to claim 29, wherein:
- the storage means comprises a central container (34), around which the at least
two separation cells (40; 100) are symmetrically arranged with respect to the rotation
axis (31); and
- the second balancing means comprises at least two interconnected flexible pouches
(81, 82, 83, 84) partially filled with a liquid, wherein the pouches (81, 82, 83,
84) are arranged against a wall of the central container (34; 341, 342, 343, 344)
so that the at least one satellite bag (2; 3; 15) connected to each separation bag
(1) presses onto a pouch (81, 82, 83, 84) during centrifugation.
31. An apparatus according to claim 29, wherein:
- the storage means comprises a central container (34), around which the at least
two separation cells (40; 100) are symmetrically arranged with respect to the rotation
axis (31); and
- the second balancing means comprises a cylindrical flexible pouch (80) partially
filled with a liquid lining a wall of the central container (34) so that the at least
one satellite bag (2; 3; 15) connected to each separation bag (1) presses onto the
pouch during centrifugation.
32. An apparatus according to claim 29, wherein:
- the storage means comprises one container (341, 342, 343, 344) associated with each
separation cell (40), the container (341, 342, 343, 344) being located between the
separation cell (40) and the rotation axis (31); and
- the second balancing means comprises one flexible pouch (81, 82, 83, 84) partially
filled with a liquid arranged against a wall of each container (341, 342, 343, 344)
so that a satellite bag (2; 3; 15) stored in the container (341, 342, 343, 344) presses
onto a pouch during centrifugation, wherein a flexible pouch (81, 82, 83, 84) in one
container (341, 342, 343, 344) is fluidly interconnected wit a pouch (81, 82, 83,
84) in another container (341, 342, 343, 344).
33. An apparatus according to one of the claims 16 to 32, further comprising:
- a storage means (34) included in the rotor (32, 34, 35) for storing at least two
first satellite bags (2) respectively connected to at least two separation bags (1)
contained in the at least two separation cells (40; 100); and
- at least one valve member (70, 71) associated with each separation cell (40; 100)
for selectively allowing or blocking a flow of fluid between a separation bag (1)
and a first satellite bag (2), wherein the at least one valve member (70, 71) is mounted
on the rotor (32, 34, 35) so as to be between the associated separation cell (40;
100) and the storage means (34), with respect to the rotation axis (31).
34. An apparatus according to one of the claims 16 to 32, further comprising:
- a storage means (341, 342, 343, 344) included in the rotor (32, 34, 35) for storing
at least two first satellite bags (2) respectively connected to at least two separation
bags (1) contained in the at least two separation cells (40); and
- at least one valve member (70, 71) associated with each separation cell (40; 100)
for selectively allowing or blocking a flow of fluid between a separation bag (1)
and a first satellite bag (2), wherein the at least one valve member (70, 71) is mounted
on the rotor (32, 34, 35) so that the storage means (341, 342, 343, 344) is between
the at least one valve member (70, 71) and the associated separation cell (40), with
respect to the rotation axis (31).
35. An apparatus according to one of the claims 16 to 34, further comprising at least
one sensor (73, 74) associated with each separation cell (40; 100) for generating
information related to a characteristic of a component separated in a separation bag
(1) within the separation cell (40; 100).
36. An apparatus according to claim 35, wherein the at least one sensor (73, 74) is mounted
on the rotor (32, 34, 35) so as to detect a characteristic of a component in a separation
bag (1) contained in the associated separation cell (40; 100).
37. An apparatus according to claim 35, wherein the at least one sensor (73, 74) is mounted
on the rotor (32, 34, 35) so as to detect a characteristic of a component in a tube
connected to a separation bag (1) contained in the associated separation cell (40;
100).
38. An apparatus according to one of the claims 16 to 37, wherein each separation cell
(40) comprises a substantially closed cavity (43) having a longitudinal axis (42)
intersecting the rotation axis (31) of the rotor (32, 34, 35) and comprising a portion
closer to the rotation axis (31) of the rotor (32, 34, 35) that is defined by four
walls converging towards the longitudinal axis (42) of the cavity.
39. An apparatus according to claim 38, wherein the longitudinal axis (42) of the cavity
of each separation cell (40) intersects the rotation axis (31) of the rotor (32, 34,
35) at an acute angle.
40. An apparatus according to one of the claims 16 to 39, wherein each separation cell
(40) comprises a cavity (43) having a bottom wall, an upper wall and a lower wall,
and the hydraulic chamber (51) is underneath a membrane (50) that is lining at least
part of either the upper wall or the lower wall of the cavity (43).
41. An apparatus according to one of the claims 16 to 39, wherein each separation cell
(40) comprises a cavity (43) having a bottom wall, an upper wall, and a lower wall,
and the hydraulic chamber comprising a flexible pouch that rests at least on part
the lower wall.
42. An apparatus according to one of the claims 40 and 41, wherein the density of the
hydraulic liquid is so selected as to be higher than the density of the component
having the highest density.
43. An apparatus according to one of the claims 16 to 39, wherein each separation cell
(100) comprises a cavity having a bottom wall, an upper wall, and lower wall, and
the hydraulic chamber is defined by an elastic socket (110) that is secured to the
separation cell (100) so as to extend between the upper wall and the lower wall.
44. An apparatus according to claims 43, wherein the density of the hydraulic liquid is
so selected as to be between the density of a first component and the density of a
second component.
45. An apparatus according to one of the claims 16 to 44, wherein each separation cell
(40; 100) comprises a securing means (48, 49; 107, 108) for securing an upper edge
of a separation bag (1) so that the upper edge is the portion of the separation bag
(1) that is the closest to the rotation axis (31).
46. An apparatus according to one of the claims 16 to 45, further comprising:
- at least one sensor (73, 74) associated with each separation cell (40; 100) for
generating information related to a characteristic of a component separated in a separation
bag (1) within the separation cell (40; 100);
- a memory unit for storing at least one change in rotation speed of the rotor (32,
34, 35); and
- a control unit (90) programmed:
- for receiving from the memory the at least one change in rotation speed, and information
generated by the at least one sensor (73, 74) associated with each separation cell
(40; 100); and
- for causing the at least one change in rotation speed in view of information generated
by one of the at least one sensor (73, 74) associated with each of the at least two
separation cells (40; 100).
47. An apparatus according to claim 46, wherein the control unit (90) is programmed for
causing the at least one change of rotation speed in view of information generated
by the first of the at least one sensor (73, 74) associated with the at least two
separation cells (40; 100) that detects a characteristic of a component separated
in a separation bag (1) within a separation cell (40; 100).
48. An apparatus according to claim 46, wherein the control unit (90) is programmed for
causing the at least one change of rotation speed in view of information generated
by the last of the at least one sensor (73, 74) associated with the at least two separation
cells (40; 100) that detects a characteristic of a component separated in a separation
bag (1) within a separation cell (40; 100).
49. An apparatus according to one of the claims 46 to 48, further comprising at least
one valve member (70, 71) associated with each separation cell (40; 100) for selectively
allowing or blocking a flow of fluid between a separation bag (1) within the separation
cell (40; 100) and a satellite bag (2; 3; 15) connected thereto, wherein the control
unit (90) is further programmed for causing at least once in a separation process
the at least one valve member (70, 71) associated with a separation cell (40; 100)
to block a flow of fluid between a separation bag (1) within the separation cell (40;
100) and a satellite bag (2; 3; 15) connected thereto following a detection of the
characteristic of a separated component by the at least one sensor (73, 74) associated
with the same separation cell (40; 100).
50. An apparatus according to one of the claims 46 to 48, further comprising at least
one valve member (70, 71) associated with each separation cell (40; 100) for selectively
allowing or blocking a flow of fluid between a separation bag (1) within the separation
cell (40; 100) and a satellite bag (2; 3; 15) connected thereto, wherein the control
unit (90) is further programmed for causing at least once in a separation process
the at least one valve member (70, 71) associated with a separation cell (40; 100)
to allow a flow of fluid between a separation bag (1) within the separation cell (40;
100) and a satellite bag (2; 3; 15) connected thereto following a detection of the
characteristic of a separated component by the at least one sensor (73, 74) associated
with another separation cell (40; 100).
51. An apparatus according to one of the claims 46 to 50, further comprising at least
one valve member (70, 71) associated with each separation cell (40; 100) for selectively
allowing or blocking a flow of fluid between a separation bag (1) within the separation
cell (40; 100) and a satellite bag (2; 3; 15) connected thereto, wherein the control
unit (90) is further programmed for:
- causing the rotor (32, 34, 35) to rotate at a sedimentation speed for separating
a least two components in at least two separation bags (1) contained in the at least
two separation cell (40; 100) respectively;
- causing the least one valve member (70, 71) associated with each separation cell
(40; 100) to allow a flow of fluid between each separation bag (1) and the satellite
bag (2; 3; 15) connected thereto;
- causing the component transferring means to transfer at least a portion of a separated
component from each of the at least two separation bags (1) into the satellite bag
(2; 3; 15) connected thereto;
- causing the least one valve member (70, 71) associated with each separation cell
(40; 100) to block a flow of fluid between the separation bag (1) within the separation
cell (40; 100) and the satellite bag connected thereto, when the sensor (73, 74) associated
with the separation cell (40; 100) detects the characteristic of a separated component.
52. An apparatus according to claim 51, wherein the control unit (90) is further programmed
for:
- causing the component transferring means to stop transferring a separated component
from the at least two separation bags (1) into the satellite bags (2; 3; 15) connected
thereto when one sensor (73, 74) associated with one of the at least two the separation
cells (40; 100) detects the characteristic of a separated component;
- causing the component transferring means to transfer a separated component from
the at least two separation bags (1) into the satellite bags (2; 3; 15) connected
thereto, after the valve member (70, 71) associated with the separation cell (40;
100) associated with the sensor (73, 74) that has detected the characteristic of a
separated component has blocked a flow of fluid between the separation bag (1) and
the satellite bag (2; 3; 15) connected thereto.
53. An apparatus according to one of the claims 51 and 52, wherein:
- the at least one sensor comprises a first sensor (73) for detecting a characteristic
of a separated component in a separation bag (1) within a separation cell (40);
- the least one valve member comprises a first valve member (70) for allowing or blocking
a flow of fluid between a separation bag (1) and a first satellite bag (2) connected
thereto;
- the control unit (90) is further programmed for controlling an actuation of the
first valve member (70) in view of information from the first sensor (73).
54. An apparatus according to claim 53, wherein:
- the at least one sensor comprises a second sensor (74) for detecting a characteristic
of a separated component in a tube connecting a separation bag (1) to a second satellite
bag (15);
- the least one valve member comprises a second valve member (71) for allowing or
blocking a flow of fluid between a separation bag (1) and a second satellite bag (15)
connected thereto;
- the control unit (90) is further programmed for controlling an actuation of a second
valve member (71) in view of information from the second sensor (74).
55. A set of bags for the separation of a composite liquid into at least two components
in a centrifuge having a rotation axis, comprising:
- a collection and separation bag (1) having a median axis, a top and a bottom, for
cooperating with a centrifuge so that the median axis of the collection and separation
bag substantially intersects the rotation axis, the bottom is the farthest from the
rotation axis and the top is the closest to the rotation axis, wherein the top of
the separation bag comprises two edges converging towards a tip located on the median
axis;
- a collection tube (5) having a first end connected to the collection and separation
bag (1); and
- at least two satellite bags (2, 3, 15) connected to the top of the collection and
separation bag (1), wherein at least one satellite bag (2, 15) in which a component
is to be transferred during a rotation of the centrifuge, is connected to the tip
of the collection and separation bag (1).
56. A set of bags according to claim 55, further comprising:
- a first flexible tube (17) having:
- a first end connected to a first satellite bag (2);
- a valve section for engaging a first pinch valve of the centrifuge;
- a second flexible tube (18) having:
- a first end connected to a second satellite bag (15);
- a valve section for engaging a second pinch valve of the centrifuge; and
- a three-way connector (16, 16a, 16b) having:
an inlet channel (20) for connection to the collection and separation bag (1);
a first outlet channel (21) connected to a second end of the first tube (17), and
a second outlet channel (22) connected to a second end of the second tube (18),
wherein the three-way connector (16, 16a, 16b) is so shaped as to allow a section
of either one of the first outlet channel (21) and the first tube (17) and a section
of either one of the second outlet channel (22) and the second tube (18) to be the
closest to the rotation axis when the first valve section is engaged in the first
pinch valve and the second valve section is engaged in the second pinch valve.
57. A bag set according to claim 56, wherein the section of either one of the first outlet
channel (21) and the first tube (17) and the section of either one of the second outlet
channel (22) and the second tube (18) that are the closest to the rotation axis when
the first valve section is engaged in the first pinch valve and the second valve section
is engaged in the second pinch valve, coincide at a meeting point of the first outlet
channel (21) and the second outlet channel (22).
58. A bag set according to claim 57, wherein the first outlet channel (21) and the second
outlet channel (22) are substantially aligned and the inlet channel (20) is perpendicular
thereto.
59. A bag set according to claim 56, wherein
- the section of either one of the first outlet channel (21) and the first tube (17)
that is the closest to the rotation axis when the first valve section is engaged in
the first pinch valve and the second valve section is engaged in the second pinch
valve comprises a section of the first tube (17) between the three way connector (16a)
and the first valve section, and
- the section of either one of the second outlet channel (22) and the second tube
(18) that is the closest to the rotation axis when the first valve section is engaged
in the first pinch valve and the second valve section is engaged in the second pinch
valve comprises a section of the second tube (18) between the three way connector
(16a) and the second valve section.
60. A bag set according to claim 59, wherein an angle between the first outlet channel
(21) and the inlet channel (20) is between 90 degrees and 180 degrees, and an angle
between the second outlet channel (22) and the inlet channel (20) is between 90 degrees
and 180 degrees.
61. A bag set according to one of the claims 56 to 60, wherein the inlet channel (20),
the first outlet channel (21), and the second outlet channel (22) join in a central
location.
62. A bag set according to one of the claims 56 to 60, wherein the first outlet channel
(21) connects to the inlet channel (20) at a first location and the second outlet
channel (22) connects to the inlet channel (20) at a second location, the first location
being closer to the rotation axis than the second location when the first valve section
is engaged in the first pinch valve and the second valve section is engaged in the
second pinch valve.
63. A bag set according to one of the claims 56 to 62, further comprising a third tube
(4) having a first end connected to the tip of the collection and separation bag (1)
and a second end connected to the inlet channel (20).
64. A bag set according to claim 63, wherein the third tube (4) comprises a detection
section for engaging a cell detector of the centrifuge.
65. A bag set according to claim 63, further comprising a breakable stopper (9) connected
to the third tube (4).
66. A bag set according to one of the claims 56 to 65, for the separation of whole blood
into a plasma component, a platelet component and a red blood cell component, wherein
the first satellite bag (2) is for collecting the plasma component and the second
satellite bag (15) is for collecting the platelet component.
67. A bag set according to claim 66, further comprising:
- a third satellite bag (3) for collecting red blood cells;
- a third tube (6) having:
- a first section having a first end connected to the top of the collection and separation
bag (1); and
- a second section having a second end connected to the third satellite bag (3); and
- a leuko-reduction filter (13) having an inlet connected to a second end of the first
section of the third tube (6) and an outlet connected to a first end of the second
section of the third tube (6).
68. A bag set according to one of the claims 66 and 67, further comprising a needle (12)
connected to a second end of the collection tube (5).